Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | */ | |
4 | ||
5 | /* | |
6 | * 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles | |
7 | * or rs-channels. It also implements echoing, cooked mode etc. | |
8 | * | |
9 | * Kill-line thanks to John T Kohl, who also corrected VMIN = VTIME = 0. | |
10 | * | |
11 | * Modified by Theodore Ts'o, 9/14/92, to dynamically allocate the | |
12 | * tty_struct and tty_queue structures. Previously there was an array | |
13 | * of 256 tty_struct's which was statically allocated, and the | |
14 | * tty_queue structures were allocated at boot time. Both are now | |
15 | * dynamically allocated only when the tty is open. | |
16 | * | |
17 | * Also restructured routines so that there is more of a separation | |
18 | * between the high-level tty routines (tty_io.c and tty_ioctl.c) and | |
19 | * the low-level tty routines (serial.c, pty.c, console.c). This | |
37bdfb07 | 20 | * makes for cleaner and more compact code. -TYT, 9/17/92 |
1da177e4 LT |
21 | * |
22 | * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines | |
23 | * which can be dynamically activated and de-activated by the line | |
24 | * discipline handling modules (like SLIP). | |
25 | * | |
26 | * NOTE: pay no attention to the line discipline code (yet); its | |
27 | * interface is still subject to change in this version... | |
28 | * -- TYT, 1/31/92 | |
29 | * | |
30 | * Added functionality to the OPOST tty handling. No delays, but all | |
31 | * other bits should be there. | |
32 | * -- Nick Holloway <alfie@dcs.warwick.ac.uk>, 27th May 1993. | |
33 | * | |
34 | * Rewrote canonical mode and added more termios flags. | |
35 | * -- julian@uhunix.uhcc.hawaii.edu (J. Cowley), 13Jan94 | |
36 | * | |
37 | * Reorganized FASYNC support so mouse code can share it. | |
38 | * -- ctm@ardi.com, 9Sep95 | |
39 | * | |
40 | * New TIOCLINUX variants added. | |
41 | * -- mj@k332.feld.cvut.cz, 19-Nov-95 | |
37bdfb07 | 42 | * |
1da177e4 LT |
43 | * Restrict vt switching via ioctl() |
44 | * -- grif@cs.ucr.edu, 5-Dec-95 | |
45 | * | |
46 | * Move console and virtual terminal code to more appropriate files, | |
47 | * implement CONFIG_VT and generalize console device interface. | |
48 | * -- Marko Kohtala <Marko.Kohtala@hut.fi>, March 97 | |
49 | * | |
d81ed103 | 50 | * Rewrote tty_init_dev and tty_release_dev to eliminate races. |
1da177e4 LT |
51 | * -- Bill Hawes <whawes@star.net>, June 97 |
52 | * | |
53 | * Added devfs support. | |
54 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 13-Jan-1998 | |
55 | * | |
56 | * Added support for a Unix98-style ptmx device. | |
57 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
58 | * | |
59 | * Reduced memory usage for older ARM systems | |
60 | * -- Russell King <rmk@arm.linux.org.uk> | |
61 | * | |
62 | * Move do_SAK() into process context. Less stack use in devfs functions. | |
37bdfb07 AC |
63 | * alloc_tty_struct() always uses kmalloc() |
64 | * -- Andrew Morton <andrewm@uow.edu.eu> 17Mar01 | |
1da177e4 LT |
65 | */ |
66 | ||
1da177e4 LT |
67 | #include <linux/types.h> |
68 | #include <linux/major.h> | |
69 | #include <linux/errno.h> | |
70 | #include <linux/signal.h> | |
71 | #include <linux/fcntl.h> | |
72 | #include <linux/sched.h> | |
73 | #include <linux/interrupt.h> | |
74 | #include <linux/tty.h> | |
75 | #include <linux/tty_driver.h> | |
76 | #include <linux/tty_flip.h> | |
77 | #include <linux/devpts_fs.h> | |
78 | #include <linux/file.h> | |
9f3acc31 | 79 | #include <linux/fdtable.h> |
1da177e4 LT |
80 | #include <linux/console.h> |
81 | #include <linux/timer.h> | |
82 | #include <linux/ctype.h> | |
83 | #include <linux/kd.h> | |
84 | #include <linux/mm.h> | |
85 | #include <linux/string.h> | |
86 | #include <linux/slab.h> | |
87 | #include <linux/poll.h> | |
88 | #include <linux/proc_fs.h> | |
89 | #include <linux/init.h> | |
90 | #include <linux/module.h> | |
1da177e4 | 91 | #include <linux/device.h> |
1da177e4 LT |
92 | #include <linux/wait.h> |
93 | #include <linux/bitops.h> | |
b20f3ae5 | 94 | #include <linux/delay.h> |
a352def2 | 95 | #include <linux/seq_file.h> |
d281da7f | 96 | #include <linux/serial.h> |
5a3c6b25 | 97 | #include <linux/ratelimit.h> |
1da177e4 | 98 | |
a352def2 | 99 | #include <linux/uaccess.h> |
1da177e4 LT |
100 | |
101 | #include <linux/kbd_kern.h> | |
102 | #include <linux/vt_kern.h> | |
103 | #include <linux/selection.h> | |
1da177e4 LT |
104 | |
105 | #include <linux/kmod.h> | |
b488893a | 106 | #include <linux/nsproxy.h> |
1da177e4 LT |
107 | |
108 | #undef TTY_DEBUG_HANGUP | |
109 | ||
110 | #define TTY_PARANOIA_CHECK 1 | |
111 | #define CHECK_TTY_COUNT 1 | |
112 | ||
edc6afc5 | 113 | struct ktermios tty_std_termios = { /* for the benefit of tty drivers */ |
1da177e4 LT |
114 | .c_iflag = ICRNL | IXON, |
115 | .c_oflag = OPOST | ONLCR, | |
116 | .c_cflag = B38400 | CS8 | CREAD | HUPCL, | |
117 | .c_lflag = ISIG | ICANON | ECHO | ECHOE | ECHOK | | |
118 | ECHOCTL | ECHOKE | IEXTEN, | |
edc6afc5 AC |
119 | .c_cc = INIT_C_CC, |
120 | .c_ispeed = 38400, | |
121 | .c_ospeed = 38400 | |
1da177e4 LT |
122 | }; |
123 | ||
124 | EXPORT_SYMBOL(tty_std_termios); | |
125 | ||
126 | /* This list gets poked at by procfs and various bits of boot up code. This | |
127 | could do with some rationalisation such as pulling the tty proc function | |
128 | into this file */ | |
37bdfb07 | 129 | |
1da177e4 LT |
130 | LIST_HEAD(tty_drivers); /* linked list of tty drivers */ |
131 | ||
24ec839c | 132 | /* Mutex to protect creating and releasing a tty. This is shared with |
1da177e4 | 133 | vt.c for deeply disgusting hack reasons */ |
70522e12 | 134 | DEFINE_MUTEX(tty_mutex); |
de2a84f2 | 135 | EXPORT_SYMBOL(tty_mutex); |
1da177e4 | 136 | |
ee2ffa0d NP |
137 | /* Spinlock to protect the tty->tty_files list */ |
138 | DEFINE_SPINLOCK(tty_files_lock); | |
139 | ||
1da177e4 LT |
140 | static ssize_t tty_read(struct file *, char __user *, size_t, loff_t *); |
141 | static ssize_t tty_write(struct file *, const char __user *, size_t, loff_t *); | |
37bdfb07 AC |
142 | ssize_t redirected_tty_write(struct file *, const char __user *, |
143 | size_t, loff_t *); | |
1da177e4 LT |
144 | static unsigned int tty_poll(struct file *, poll_table *); |
145 | static int tty_open(struct inode *, struct file *); | |
04f378b1 | 146 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg); |
e10cc1df | 147 | #ifdef CONFIG_COMPAT |
37bdfb07 | 148 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
149 | unsigned long arg); |
150 | #else | |
151 | #define tty_compat_ioctl NULL | |
152 | #endif | |
ec79d605 | 153 | static int __tty_fasync(int fd, struct file *filp, int on); |
37bdfb07 | 154 | static int tty_fasync(int fd, struct file *filp, int on); |
d5698c28 | 155 | static void release_tty(struct tty_struct *tty, int idx); |
2a65f1d9 | 156 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
98a27ba4 | 157 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty); |
1da177e4 | 158 | |
af9b897e AC |
159 | /** |
160 | * alloc_tty_struct - allocate a tty object | |
161 | * | |
162 | * Return a new empty tty structure. The data fields have not | |
163 | * been initialized in any way but has been zeroed | |
164 | * | |
165 | * Locking: none | |
af9b897e | 166 | */ |
1da177e4 | 167 | |
bf970ee4 | 168 | struct tty_struct *alloc_tty_struct(void) |
1da177e4 | 169 | { |
1266b1e1 | 170 | return kzalloc(sizeof(struct tty_struct), GFP_KERNEL); |
1da177e4 LT |
171 | } |
172 | ||
af9b897e AC |
173 | /** |
174 | * free_tty_struct - free a disused tty | |
175 | * @tty: tty struct to free | |
176 | * | |
177 | * Free the write buffers, tty queue and tty memory itself. | |
178 | * | |
179 | * Locking: none. Must be called after tty is definitely unused | |
180 | */ | |
181 | ||
bf970ee4 | 182 | void free_tty_struct(struct tty_struct *tty) |
1da177e4 | 183 | { |
30004ac9 DES |
184 | if (tty->dev) |
185 | put_device(tty->dev); | |
1da177e4 | 186 | kfree(tty->write_buf); |
33f0f88f | 187 | tty_buffer_free_all(tty); |
d29f3ef3 | 188 | tty->magic = 0xDEADDEAD; |
1da177e4 LT |
189 | kfree(tty); |
190 | } | |
191 | ||
d996b62a NP |
192 | static inline struct tty_struct *file_tty(struct file *file) |
193 | { | |
194 | return ((struct tty_file_private *)file->private_data)->tty; | |
195 | } | |
196 | ||
fa90e1c9 | 197 | int tty_alloc_file(struct file *file) |
d996b62a NP |
198 | { |
199 | struct tty_file_private *priv; | |
200 | ||
f573bd17 PE |
201 | priv = kmalloc(sizeof(*priv), GFP_KERNEL); |
202 | if (!priv) | |
203 | return -ENOMEM; | |
d996b62a | 204 | |
fa90e1c9 JS |
205 | file->private_data = priv; |
206 | ||
207 | return 0; | |
208 | } | |
209 | ||
210 | /* Associate a new file with the tty structure */ | |
211 | void tty_add_file(struct tty_struct *tty, struct file *file) | |
212 | { | |
213 | struct tty_file_private *priv = file->private_data; | |
214 | ||
d996b62a NP |
215 | priv->tty = tty; |
216 | priv->file = file; | |
d996b62a NP |
217 | |
218 | spin_lock(&tty_files_lock); | |
219 | list_add(&priv->list, &tty->tty_files); | |
220 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 221 | } |
f573bd17 | 222 | |
fa90e1c9 JS |
223 | /** |
224 | * tty_free_file - free file->private_data | |
225 | * | |
226 | * This shall be used only for fail path handling when tty_add_file was not | |
227 | * called yet. | |
228 | */ | |
229 | void tty_free_file(struct file *file) | |
230 | { | |
231 | struct tty_file_private *priv = file->private_data; | |
232 | ||
233 | file->private_data = NULL; | |
234 | kfree(priv); | |
d996b62a NP |
235 | } |
236 | ||
237 | /* Delete file from its tty */ | |
238 | void tty_del_file(struct file *file) | |
239 | { | |
240 | struct tty_file_private *priv = file->private_data; | |
241 | ||
242 | spin_lock(&tty_files_lock); | |
243 | list_del(&priv->list); | |
244 | spin_unlock(&tty_files_lock); | |
fa90e1c9 | 245 | tty_free_file(file); |
d996b62a NP |
246 | } |
247 | ||
248 | ||
1da177e4 LT |
249 | #define TTY_NUMBER(tty) ((tty)->index + (tty)->driver->name_base) |
250 | ||
af9b897e AC |
251 | /** |
252 | * tty_name - return tty naming | |
253 | * @tty: tty structure | |
254 | * @buf: buffer for output | |
255 | * | |
256 | * Convert a tty structure into a name. The name reflects the kernel | |
257 | * naming policy and if udev is in use may not reflect user space | |
258 | * | |
259 | * Locking: none | |
260 | */ | |
261 | ||
1da177e4 LT |
262 | char *tty_name(struct tty_struct *tty, char *buf) |
263 | { | |
264 | if (!tty) /* Hmm. NULL pointer. That's fun. */ | |
265 | strcpy(buf, "NULL tty"); | |
266 | else | |
267 | strcpy(buf, tty->name); | |
268 | return buf; | |
269 | } | |
270 | ||
271 | EXPORT_SYMBOL(tty_name); | |
272 | ||
d769a669 | 273 | int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, |
1da177e4 LT |
274 | const char *routine) |
275 | { | |
276 | #ifdef TTY_PARANOIA_CHECK | |
277 | if (!tty) { | |
278 | printk(KERN_WARNING | |
279 | "null TTY for (%d:%d) in %s\n", | |
280 | imajor(inode), iminor(inode), routine); | |
281 | return 1; | |
282 | } | |
283 | if (tty->magic != TTY_MAGIC) { | |
284 | printk(KERN_WARNING | |
285 | "bad magic number for tty struct (%d:%d) in %s\n", | |
286 | imajor(inode), iminor(inode), routine); | |
287 | return 1; | |
288 | } | |
289 | #endif | |
290 | return 0; | |
291 | } | |
292 | ||
293 | static int check_tty_count(struct tty_struct *tty, const char *routine) | |
294 | { | |
295 | #ifdef CHECK_TTY_COUNT | |
296 | struct list_head *p; | |
297 | int count = 0; | |
37bdfb07 | 298 | |
ee2ffa0d | 299 | spin_lock(&tty_files_lock); |
1da177e4 LT |
300 | list_for_each(p, &tty->tty_files) { |
301 | count++; | |
302 | } | |
ee2ffa0d | 303 | spin_unlock(&tty_files_lock); |
1da177e4 LT |
304 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
305 | tty->driver->subtype == PTY_TYPE_SLAVE && | |
306 | tty->link && tty->link->count) | |
307 | count++; | |
308 | if (tty->count != count) { | |
309 | printk(KERN_WARNING "Warning: dev (%s) tty->count(%d) " | |
310 | "!= #fd's(%d) in %s\n", | |
311 | tty->name, tty->count, count, routine); | |
312 | return count; | |
24ec839c | 313 | } |
1da177e4 LT |
314 | #endif |
315 | return 0; | |
316 | } | |
317 | ||
af9b897e AC |
318 | /** |
319 | * get_tty_driver - find device of a tty | |
320 | * @dev_t: device identifier | |
321 | * @index: returns the index of the tty | |
322 | * | |
323 | * This routine returns a tty driver structure, given a device number | |
324 | * and also passes back the index number. | |
325 | * | |
326 | * Locking: caller must hold tty_mutex | |
1da177e4 | 327 | */ |
af9b897e | 328 | |
1da177e4 LT |
329 | static struct tty_driver *get_tty_driver(dev_t device, int *index) |
330 | { | |
331 | struct tty_driver *p; | |
332 | ||
333 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
334 | dev_t base = MKDEV(p->major, p->minor_start); | |
335 | if (device < base || device >= base + p->num) | |
336 | continue; | |
337 | *index = device - base; | |
7d7b93c1 | 338 | return tty_driver_kref_get(p); |
1da177e4 LT |
339 | } |
340 | return NULL; | |
341 | } | |
342 | ||
f2d937f3 JW |
343 | #ifdef CONFIG_CONSOLE_POLL |
344 | ||
345 | /** | |
346 | * tty_find_polling_driver - find device of a polled tty | |
347 | * @name: name string to match | |
348 | * @line: pointer to resulting tty line nr | |
349 | * | |
350 | * This routine returns a tty driver structure, given a name | |
351 | * and the condition that the tty driver is capable of polled | |
352 | * operation. | |
353 | */ | |
354 | struct tty_driver *tty_find_polling_driver(char *name, int *line) | |
355 | { | |
356 | struct tty_driver *p, *res = NULL; | |
357 | int tty_line = 0; | |
0dca0fd2 | 358 | int len; |
5f0878ac | 359 | char *str, *stp; |
f2d937f3 | 360 | |
0dca0fd2 JW |
361 | for (str = name; *str; str++) |
362 | if ((*str >= '0' && *str <= '9') || *str == ',') | |
363 | break; | |
364 | if (!*str) | |
365 | return NULL; | |
366 | ||
367 | len = str - name; | |
368 | tty_line = simple_strtoul(str, &str, 10); | |
369 | ||
f2d937f3 JW |
370 | mutex_lock(&tty_mutex); |
371 | /* Search through the tty devices to look for a match */ | |
372 | list_for_each_entry(p, &tty_drivers, tty_drivers) { | |
0dca0fd2 JW |
373 | if (strncmp(name, p->name, len) != 0) |
374 | continue; | |
5f0878ac AC |
375 | stp = str; |
376 | if (*stp == ',') | |
377 | stp++; | |
378 | if (*stp == '\0') | |
379 | stp = NULL; | |
f2d937f3 | 380 | |
6eb68d6f | 381 | if (tty_line >= 0 && tty_line < p->num && p->ops && |
5f0878ac | 382 | p->ops->poll_init && !p->ops->poll_init(p, tty_line, stp)) { |
7d7b93c1 | 383 | res = tty_driver_kref_get(p); |
f2d937f3 JW |
384 | *line = tty_line; |
385 | break; | |
386 | } | |
387 | } | |
388 | mutex_unlock(&tty_mutex); | |
389 | ||
390 | return res; | |
391 | } | |
392 | EXPORT_SYMBOL_GPL(tty_find_polling_driver); | |
393 | #endif | |
394 | ||
af9b897e AC |
395 | /** |
396 | * tty_check_change - check for POSIX terminal changes | |
397 | * @tty: tty to check | |
398 | * | |
399 | * If we try to write to, or set the state of, a terminal and we're | |
400 | * not in the foreground, send a SIGTTOU. If the signal is blocked or | |
401 | * ignored, go ahead and perform the operation. (POSIX 7.2) | |
402 | * | |
978e595f | 403 | * Locking: ctrl_lock |
1da177e4 | 404 | */ |
af9b897e | 405 | |
37bdfb07 | 406 | int tty_check_change(struct tty_struct *tty) |
1da177e4 | 407 | { |
47f86834 AC |
408 | unsigned long flags; |
409 | int ret = 0; | |
410 | ||
1da177e4 LT |
411 | if (current->signal->tty != tty) |
412 | return 0; | |
47f86834 AC |
413 | |
414 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
415 | ||
ab521dc0 EB |
416 | if (!tty->pgrp) { |
417 | printk(KERN_WARNING "tty_check_change: tty->pgrp == NULL!\n"); | |
9ffee4cb | 418 | goto out_unlock; |
1da177e4 | 419 | } |
ab521dc0 | 420 | if (task_pgrp(current) == tty->pgrp) |
9ffee4cb AM |
421 | goto out_unlock; |
422 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 423 | if (is_ignored(SIGTTOU)) |
47f86834 AC |
424 | goto out; |
425 | if (is_current_pgrp_orphaned()) { | |
426 | ret = -EIO; | |
427 | goto out; | |
428 | } | |
040b6362 ON |
429 | kill_pgrp(task_pgrp(current), SIGTTOU, 1); |
430 | set_thread_flag(TIF_SIGPENDING); | |
47f86834 AC |
431 | ret = -ERESTARTSYS; |
432 | out: | |
9ffee4cb AM |
433 | return ret; |
434 | out_unlock: | |
47f86834 AC |
435 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
436 | return ret; | |
1da177e4 LT |
437 | } |
438 | ||
439 | EXPORT_SYMBOL(tty_check_change); | |
440 | ||
37bdfb07 | 441 | static ssize_t hung_up_tty_read(struct file *file, char __user *buf, |
1da177e4 LT |
442 | size_t count, loff_t *ppos) |
443 | { | |
444 | return 0; | |
445 | } | |
446 | ||
37bdfb07 | 447 | static ssize_t hung_up_tty_write(struct file *file, const char __user *buf, |
1da177e4 LT |
448 | size_t count, loff_t *ppos) |
449 | { | |
450 | return -EIO; | |
451 | } | |
452 | ||
453 | /* No kernel lock held - none needed ;) */ | |
37bdfb07 | 454 | static unsigned int hung_up_tty_poll(struct file *filp, poll_table *wait) |
1da177e4 LT |
455 | { |
456 | return POLLIN | POLLOUT | POLLERR | POLLHUP | POLLRDNORM | POLLWRNORM; | |
457 | } | |
458 | ||
04f378b1 AC |
459 | static long hung_up_tty_ioctl(struct file *file, unsigned int cmd, |
460 | unsigned long arg) | |
38ad2ed0 PF |
461 | { |
462 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
463 | } | |
464 | ||
37bdfb07 | 465 | static long hung_up_tty_compat_ioctl(struct file *file, |
38ad2ed0 | 466 | unsigned int cmd, unsigned long arg) |
1da177e4 LT |
467 | { |
468 | return cmd == TIOCSPGRP ? -ENOTTY : -EIO; | |
469 | } | |
470 | ||
62322d25 | 471 | static const struct file_operations tty_fops = { |
1da177e4 LT |
472 | .llseek = no_llseek, |
473 | .read = tty_read, | |
474 | .write = tty_write, | |
475 | .poll = tty_poll, | |
04f378b1 | 476 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 477 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
478 | .open = tty_open, |
479 | .release = tty_release, | |
480 | .fasync = tty_fasync, | |
481 | }; | |
482 | ||
62322d25 | 483 | static const struct file_operations console_fops = { |
1da177e4 LT |
484 | .llseek = no_llseek, |
485 | .read = tty_read, | |
486 | .write = redirected_tty_write, | |
487 | .poll = tty_poll, | |
04f378b1 | 488 | .unlocked_ioctl = tty_ioctl, |
e10cc1df | 489 | .compat_ioctl = tty_compat_ioctl, |
1da177e4 LT |
490 | .open = tty_open, |
491 | .release = tty_release, | |
492 | .fasync = tty_fasync, | |
493 | }; | |
494 | ||
62322d25 | 495 | static const struct file_operations hung_up_tty_fops = { |
1da177e4 LT |
496 | .llseek = no_llseek, |
497 | .read = hung_up_tty_read, | |
498 | .write = hung_up_tty_write, | |
499 | .poll = hung_up_tty_poll, | |
04f378b1 | 500 | .unlocked_ioctl = hung_up_tty_ioctl, |
38ad2ed0 | 501 | .compat_ioctl = hung_up_tty_compat_ioctl, |
1da177e4 LT |
502 | .release = tty_release, |
503 | }; | |
504 | ||
505 | static DEFINE_SPINLOCK(redirect_lock); | |
506 | static struct file *redirect; | |
507 | ||
508 | /** | |
509 | * tty_wakeup - request more data | |
510 | * @tty: terminal | |
511 | * | |
512 | * Internal and external helper for wakeups of tty. This function | |
513 | * informs the line discipline if present that the driver is ready | |
514 | * to receive more output data. | |
515 | */ | |
37bdfb07 | 516 | |
1da177e4 LT |
517 | void tty_wakeup(struct tty_struct *tty) |
518 | { | |
519 | struct tty_ldisc *ld; | |
37bdfb07 | 520 | |
1da177e4 LT |
521 | if (test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) { |
522 | ld = tty_ldisc_ref(tty); | |
37bdfb07 | 523 | if (ld) { |
a352def2 AC |
524 | if (ld->ops->write_wakeup) |
525 | ld->ops->write_wakeup(tty); | |
1da177e4 LT |
526 | tty_ldisc_deref(ld); |
527 | } | |
528 | } | |
4b19449d | 529 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
530 | } |
531 | ||
532 | EXPORT_SYMBOL_GPL(tty_wakeup); | |
533 | ||
af9b897e | 534 | /** |
11dbf203 | 535 | * __tty_hangup - actual handler for hangup events |
65f27f38 | 536 | * @work: tty device |
af9b897e | 537 | * |
1bad879a | 538 | * This can be called by the "eventd" kernel thread. That is process |
af9b897e AC |
539 | * synchronous but doesn't hold any locks, so we need to make sure we |
540 | * have the appropriate locks for what we're doing. | |
541 | * | |
542 | * The hangup event clears any pending redirections onto the hung up | |
543 | * device. It ensures future writes will error and it does the needed | |
544 | * line discipline hangup and signal delivery. The tty object itself | |
545 | * remains intact. | |
546 | * | |
547 | * Locking: | |
ec79d605 | 548 | * BTM |
24ec839c PZ |
549 | * redirect lock for undoing redirection |
550 | * file list lock for manipulating list of ttys | |
551 | * tty_ldisc_lock from called functions | |
552 | * termios_mutex resetting termios data | |
553 | * tasklist_lock to walk task list for hangup event | |
554 | * ->siglock to protect ->signal/->sighand | |
1da177e4 | 555 | */ |
11dbf203 | 556 | void __tty_hangup(struct tty_struct *tty) |
1da177e4 | 557 | { |
37bdfb07 | 558 | struct file *cons_filp = NULL; |
1da177e4 LT |
559 | struct file *filp, *f = NULL; |
560 | struct task_struct *p; | |
d996b62a | 561 | struct tty_file_private *priv; |
1da177e4 | 562 | int closecount = 0, n; |
47f86834 | 563 | unsigned long flags; |
9c9f4ded | 564 | int refs = 0; |
1da177e4 LT |
565 | |
566 | if (!tty) | |
567 | return; | |
568 | ||
1da177e4 LT |
569 | |
570 | spin_lock(&redirect_lock); | |
d996b62a | 571 | if (redirect && file_tty(redirect) == tty) { |
1da177e4 LT |
572 | f = redirect; |
573 | redirect = NULL; | |
574 | } | |
575 | spin_unlock(&redirect_lock); | |
37bdfb07 | 576 | |
d29f3ef3 | 577 | tty_lock(tty); |
11dbf203 | 578 | |
acfa747b JS |
579 | /* some functions below drop BTM, so we need this bit */ |
580 | set_bit(TTY_HUPPING, &tty->flags); | |
581 | ||
ec79d605 AB |
582 | /* inuse_filps is protected by the single tty lock, |
583 | this really needs to change if we want to flush the | |
584 | workqueue with the lock held */ | |
11dbf203 | 585 | check_tty_count(tty, "tty_hangup"); |
36ba782e | 586 | |
ee2ffa0d | 587 | spin_lock(&tty_files_lock); |
1da177e4 | 588 | /* This breaks for file handles being sent over AF_UNIX sockets ? */ |
d996b62a NP |
589 | list_for_each_entry(priv, &tty->tty_files, list) { |
590 | filp = priv->file; | |
1da177e4 LT |
591 | if (filp->f_op->write == redirected_tty_write) |
592 | cons_filp = filp; | |
593 | if (filp->f_op->write != tty_write) | |
594 | continue; | |
595 | closecount++; | |
ec79d605 | 596 | __tty_fasync(-1, filp, 0); /* can't block */ |
1da177e4 LT |
597 | filp->f_op = &hung_up_tty_fops; |
598 | } | |
ee2ffa0d | 599 | spin_unlock(&tty_files_lock); |
37bdfb07 | 600 | |
acfa747b JS |
601 | /* |
602 | * it drops BTM and thus races with reopen | |
603 | * we protect the race by TTY_HUPPING | |
604 | */ | |
c65c9bc3 | 605 | tty_ldisc_hangup(tty); |
37bdfb07 | 606 | |
1da177e4 | 607 | read_lock(&tasklist_lock); |
ab521dc0 EB |
608 | if (tty->session) { |
609 | do_each_pid_task(tty->session, PIDTYPE_SID, p) { | |
24ec839c | 610 | spin_lock_irq(&p->sighand->siglock); |
9c9f4ded | 611 | if (p->signal->tty == tty) { |
1da177e4 | 612 | p->signal->tty = NULL; |
9c9f4ded AC |
613 | /* We defer the dereferences outside fo |
614 | the tasklist lock */ | |
615 | refs++; | |
616 | } | |
24ec839c PZ |
617 | if (!p->signal->leader) { |
618 | spin_unlock_irq(&p->sighand->siglock); | |
1da177e4 | 619 | continue; |
24ec839c PZ |
620 | } |
621 | __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); | |
622 | __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); | |
ab521dc0 | 623 | put_pid(p->signal->tty_old_pgrp); /* A noop */ |
47f86834 | 624 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
625 | if (tty->pgrp) |
626 | p->signal->tty_old_pgrp = get_pid(tty->pgrp); | |
47f86834 | 627 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
24ec839c | 628 | spin_unlock_irq(&p->sighand->siglock); |
ab521dc0 | 629 | } while_each_pid_task(tty->session, PIDTYPE_SID, p); |
1da177e4 LT |
630 | } |
631 | read_unlock(&tasklist_lock); | |
632 | ||
47f86834 | 633 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
c65c9bc3 AC |
634 | clear_bit(TTY_THROTTLED, &tty->flags); |
635 | clear_bit(TTY_PUSH, &tty->flags); | |
636 | clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
d9c1e9a8 EB |
637 | put_pid(tty->session); |
638 | put_pid(tty->pgrp); | |
ab521dc0 EB |
639 | tty->session = NULL; |
640 | tty->pgrp = NULL; | |
1da177e4 | 641 | tty->ctrl_status = 0; |
47f86834 AC |
642 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
643 | ||
9c9f4ded AC |
644 | /* Account for the p->signal references we killed */ |
645 | while (refs--) | |
646 | tty_kref_put(tty); | |
647 | ||
1da177e4 | 648 | /* |
37bdfb07 AC |
649 | * If one of the devices matches a console pointer, we |
650 | * cannot just call hangup() because that will cause | |
651 | * tty->count and state->count to go out of sync. | |
652 | * So we just call close() the right number of times. | |
1da177e4 LT |
653 | */ |
654 | if (cons_filp) { | |
f34d7a5b | 655 | if (tty->ops->close) |
1da177e4 | 656 | for (n = 0; n < closecount; n++) |
f34d7a5b AC |
657 | tty->ops->close(tty, cons_filp); |
658 | } else if (tty->ops->hangup) | |
659 | (tty->ops->hangup)(tty); | |
37bdfb07 AC |
660 | /* |
661 | * We don't want to have driver/ldisc interactions beyond | |
662 | * the ones we did here. The driver layer expects no | |
663 | * calls after ->hangup() from the ldisc side. However we | |
664 | * can't yet guarantee all that. | |
665 | */ | |
1da177e4 | 666 | set_bit(TTY_HUPPED, &tty->flags); |
acfa747b | 667 | clear_bit(TTY_HUPPING, &tty->flags); |
c65c9bc3 | 668 | tty_ldisc_enable(tty); |
11dbf203 | 669 | |
d29f3ef3 | 670 | tty_unlock(tty); |
11dbf203 | 671 | |
1da177e4 LT |
672 | if (f) |
673 | fput(f); | |
674 | } | |
675 | ||
ddcd9fb6 AB |
676 | static void do_tty_hangup(struct work_struct *work) |
677 | { | |
678 | struct tty_struct *tty = | |
679 | container_of(work, struct tty_struct, hangup_work); | |
680 | ||
11dbf203 | 681 | __tty_hangup(tty); |
ddcd9fb6 AB |
682 | } |
683 | ||
af9b897e AC |
684 | /** |
685 | * tty_hangup - trigger a hangup event | |
686 | * @tty: tty to hangup | |
687 | * | |
688 | * A carrier loss (virtual or otherwise) has occurred on this like | |
689 | * schedule a hangup sequence to run after this event. | |
690 | */ | |
691 | ||
37bdfb07 | 692 | void tty_hangup(struct tty_struct *tty) |
1da177e4 LT |
693 | { |
694 | #ifdef TTY_DEBUG_HANGUP | |
695 | char buf[64]; | |
1da177e4 LT |
696 | printk(KERN_DEBUG "%s hangup...\n", tty_name(tty, buf)); |
697 | #endif | |
698 | schedule_work(&tty->hangup_work); | |
699 | } | |
700 | ||
701 | EXPORT_SYMBOL(tty_hangup); | |
702 | ||
af9b897e AC |
703 | /** |
704 | * tty_vhangup - process vhangup | |
705 | * @tty: tty to hangup | |
706 | * | |
707 | * The user has asked via system call for the terminal to be hung up. | |
708 | * We do this synchronously so that when the syscall returns the process | |
3a4fa0a2 | 709 | * is complete. That guarantee is necessary for security reasons. |
af9b897e AC |
710 | */ |
711 | ||
37bdfb07 | 712 | void tty_vhangup(struct tty_struct *tty) |
1da177e4 LT |
713 | { |
714 | #ifdef TTY_DEBUG_HANGUP | |
715 | char buf[64]; | |
716 | ||
717 | printk(KERN_DEBUG "%s vhangup...\n", tty_name(tty, buf)); | |
718 | #endif | |
11dbf203 | 719 | __tty_hangup(tty); |
1da177e4 | 720 | } |
37bdfb07 | 721 | |
1da177e4 LT |
722 | EXPORT_SYMBOL(tty_vhangup); |
723 | ||
11dbf203 | 724 | |
2cb5998b AC |
725 | /** |
726 | * tty_vhangup_self - process vhangup for own ctty | |
727 | * | |
728 | * Perform a vhangup on the current controlling tty | |
729 | */ | |
730 | ||
731 | void tty_vhangup_self(void) | |
732 | { | |
733 | struct tty_struct *tty; | |
734 | ||
2cb5998b AC |
735 | tty = get_current_tty(); |
736 | if (tty) { | |
737 | tty_vhangup(tty); | |
738 | tty_kref_put(tty); | |
739 | } | |
2cb5998b AC |
740 | } |
741 | ||
af9b897e AC |
742 | /** |
743 | * tty_hung_up_p - was tty hung up | |
744 | * @filp: file pointer of tty | |
745 | * | |
746 | * Return true if the tty has been subject to a vhangup or a carrier | |
747 | * loss | |
748 | */ | |
749 | ||
37bdfb07 | 750 | int tty_hung_up_p(struct file *filp) |
1da177e4 LT |
751 | { |
752 | return (filp->f_op == &hung_up_tty_fops); | |
753 | } | |
754 | ||
755 | EXPORT_SYMBOL(tty_hung_up_p); | |
756 | ||
ab521dc0 | 757 | static void session_clear_tty(struct pid *session) |
24ec839c PZ |
758 | { |
759 | struct task_struct *p; | |
ab521dc0 | 760 | do_each_pid_task(session, PIDTYPE_SID, p) { |
24ec839c | 761 | proc_clear_tty(p); |
ab521dc0 | 762 | } while_each_pid_task(session, PIDTYPE_SID, p); |
24ec839c PZ |
763 | } |
764 | ||
af9b897e AC |
765 | /** |
766 | * disassociate_ctty - disconnect controlling tty | |
767 | * @on_exit: true if exiting so need to "hang up" the session | |
1da177e4 | 768 | * |
af9b897e AC |
769 | * This function is typically called only by the session leader, when |
770 | * it wants to disassociate itself from its controlling tty. | |
771 | * | |
772 | * It performs the following functions: | |
1da177e4 LT |
773 | * (1) Sends a SIGHUP and SIGCONT to the foreground process group |
774 | * (2) Clears the tty from being controlling the session | |
775 | * (3) Clears the controlling tty for all processes in the | |
776 | * session group. | |
777 | * | |
af9b897e AC |
778 | * The argument on_exit is set to 1 if called when a process is |
779 | * exiting; it is 0 if called by the ioctl TIOCNOTTY. | |
780 | * | |
24ec839c | 781 | * Locking: |
ec79d605 AB |
782 | * BTM is taken for hysterical raisins, and held when |
783 | * called from no_tty(). | |
24ec839c PZ |
784 | * tty_mutex is taken to protect tty |
785 | * ->siglock is taken to protect ->signal/->sighand | |
786 | * tasklist_lock is taken to walk process list for sessions | |
787 | * ->siglock is taken to protect ->signal/->sighand | |
1da177e4 | 788 | */ |
af9b897e | 789 | |
1da177e4 LT |
790 | void disassociate_ctty(int on_exit) |
791 | { | |
792 | struct tty_struct *tty; | |
1da177e4 | 793 | |
5ec93d11 AC |
794 | if (!current->signal->leader) |
795 | return; | |
1da177e4 | 796 | |
24ec839c | 797 | tty = get_current_tty(); |
1da177e4 | 798 | if (tty) { |
1411dc4a | 799 | struct pid *tty_pgrp = get_pid(tty->pgrp); |
ddcd9fb6 | 800 | if (on_exit) { |
ddcd9fb6 | 801 | if (tty->driver->type != TTY_DRIVER_TYPE_PTY) |
11dbf203 | 802 | tty_vhangup(tty); |
ddcd9fb6 | 803 | } |
452a00d2 | 804 | tty_kref_put(tty); |
1411dc4a JS |
805 | if (tty_pgrp) { |
806 | kill_pgrp(tty_pgrp, SIGHUP, on_exit); | |
807 | if (!on_exit) | |
808 | kill_pgrp(tty_pgrp, SIGCONT, on_exit); | |
809 | put_pid(tty_pgrp); | |
810 | } | |
680a9671 | 811 | } else if (on_exit) { |
ab521dc0 | 812 | struct pid *old_pgrp; |
680a9671 EB |
813 | spin_lock_irq(¤t->sighand->siglock); |
814 | old_pgrp = current->signal->tty_old_pgrp; | |
ab521dc0 | 815 | current->signal->tty_old_pgrp = NULL; |
680a9671 | 816 | spin_unlock_irq(¤t->sighand->siglock); |
24ec839c | 817 | if (old_pgrp) { |
ab521dc0 EB |
818 | kill_pgrp(old_pgrp, SIGHUP, on_exit); |
819 | kill_pgrp(old_pgrp, SIGCONT, on_exit); | |
820 | put_pid(old_pgrp); | |
1da177e4 | 821 | } |
1da177e4 LT |
822 | return; |
823 | } | |
1da177e4 | 824 | |
24ec839c | 825 | spin_lock_irq(¤t->sighand->siglock); |
2a65f1d9 | 826 | put_pid(current->signal->tty_old_pgrp); |
23cac8de | 827 | current->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
828 | spin_unlock_irq(¤t->sighand->siglock); |
829 | ||
24ec839c PZ |
830 | tty = get_current_tty(); |
831 | if (tty) { | |
47f86834 AC |
832 | unsigned long flags; |
833 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
ab521dc0 EB |
834 | put_pid(tty->session); |
835 | put_pid(tty->pgrp); | |
836 | tty->session = NULL; | |
837 | tty->pgrp = NULL; | |
47f86834 | 838 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
452a00d2 | 839 | tty_kref_put(tty); |
24ec839c PZ |
840 | } else { |
841 | #ifdef TTY_DEBUG_HANGUP | |
842 | printk(KERN_DEBUG "error attempted to write to tty [0x%p]" | |
843 | " = NULL", tty); | |
844 | #endif | |
845 | } | |
1da177e4 LT |
846 | |
847 | /* Now clear signal->tty under the lock */ | |
848 | read_lock(&tasklist_lock); | |
ab521dc0 | 849 | session_clear_tty(task_session(current)); |
1da177e4 | 850 | read_unlock(&tasklist_lock); |
1da177e4 LT |
851 | } |
852 | ||
98a27ba4 EB |
853 | /** |
854 | * | |
855 | * no_tty - Ensure the current process does not have a controlling tty | |
856 | */ | |
857 | void no_tty(void) | |
858 | { | |
3af502b9 AC |
859 | /* FIXME: Review locking here. The tty_lock never covered any race |
860 | between a new association and proc_clear_tty but possible we need | |
861 | to protect against this anyway */ | |
98a27ba4 | 862 | struct task_struct *tsk = current; |
5ec93d11 | 863 | disassociate_ctty(0); |
98a27ba4 EB |
864 | proc_clear_tty(tsk); |
865 | } | |
866 | ||
af9b897e AC |
867 | |
868 | /** | |
beb7dd86 | 869 | * stop_tty - propagate flow control |
af9b897e AC |
870 | * @tty: tty to stop |
871 | * | |
872 | * Perform flow control to the driver. For PTY/TTY pairs we | |
beb7dd86 | 873 | * must also propagate the TIOCKPKT status. May be called |
af9b897e AC |
874 | * on an already stopped device and will not re-call the driver |
875 | * method. | |
876 | * | |
877 | * This functionality is used by both the line disciplines for | |
878 | * halting incoming flow and by the driver. It may therefore be | |
879 | * called from any context, may be under the tty atomic_write_lock | |
880 | * but not always. | |
881 | * | |
882 | * Locking: | |
04f378b1 | 883 | * Uses the tty control lock internally |
af9b897e AC |
884 | */ |
885 | ||
1da177e4 LT |
886 | void stop_tty(struct tty_struct *tty) |
887 | { | |
04f378b1 AC |
888 | unsigned long flags; |
889 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
890 | if (tty->stopped) { | |
891 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 892 | return; |
04f378b1 | 893 | } |
1da177e4 LT |
894 | tty->stopped = 1; |
895 | if (tty->link && tty->link->packet) { | |
896 | tty->ctrl_status &= ~TIOCPKT_START; | |
897 | tty->ctrl_status |= TIOCPKT_STOP; | |
4b19449d | 898 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 899 | } |
04f378b1 | 900 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
901 | if (tty->ops->stop) |
902 | (tty->ops->stop)(tty); | |
1da177e4 LT |
903 | } |
904 | ||
905 | EXPORT_SYMBOL(stop_tty); | |
906 | ||
af9b897e | 907 | /** |
beb7dd86 | 908 | * start_tty - propagate flow control |
af9b897e AC |
909 | * @tty: tty to start |
910 | * | |
911 | * Start a tty that has been stopped if at all possible. Perform | |
3a4fa0a2 | 912 | * any necessary wakeups and propagate the TIOCPKT status. If this |
af9b897e AC |
913 | * is the tty was previous stopped and is being started then the |
914 | * driver start method is invoked and the line discipline woken. | |
915 | * | |
916 | * Locking: | |
04f378b1 | 917 | * ctrl_lock |
af9b897e AC |
918 | */ |
919 | ||
1da177e4 LT |
920 | void start_tty(struct tty_struct *tty) |
921 | { | |
04f378b1 AC |
922 | unsigned long flags; |
923 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
924 | if (!tty->stopped || tty->flow_stopped) { | |
925 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
1da177e4 | 926 | return; |
04f378b1 | 927 | } |
1da177e4 LT |
928 | tty->stopped = 0; |
929 | if (tty->link && tty->link->packet) { | |
930 | tty->ctrl_status &= ~TIOCPKT_STOP; | |
931 | tty->ctrl_status |= TIOCPKT_START; | |
4b19449d | 932 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
1da177e4 | 933 | } |
04f378b1 | 934 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
f34d7a5b AC |
935 | if (tty->ops->start) |
936 | (tty->ops->start)(tty); | |
1da177e4 LT |
937 | /* If we have a running line discipline it may need kicking */ |
938 | tty_wakeup(tty); | |
1da177e4 LT |
939 | } |
940 | ||
941 | EXPORT_SYMBOL(start_tty); | |
942 | ||
af9b897e AC |
943 | /** |
944 | * tty_read - read method for tty device files | |
945 | * @file: pointer to tty file | |
946 | * @buf: user buffer | |
947 | * @count: size of user buffer | |
948 | * @ppos: unused | |
949 | * | |
950 | * Perform the read system call function on this terminal device. Checks | |
951 | * for hung up devices before calling the line discipline method. | |
952 | * | |
953 | * Locking: | |
47f86834 AC |
954 | * Locks the line discipline internally while needed. Multiple |
955 | * read calls may be outstanding in parallel. | |
af9b897e AC |
956 | */ |
957 | ||
37bdfb07 | 958 | static ssize_t tty_read(struct file *file, char __user *buf, size_t count, |
1da177e4 LT |
959 | loff_t *ppos) |
960 | { | |
961 | int i; | |
d996b62a NP |
962 | struct inode *inode = file->f_path.dentry->d_inode; |
963 | struct tty_struct *tty = file_tty(file); | |
1da177e4 LT |
964 | struct tty_ldisc *ld; |
965 | ||
1da177e4 LT |
966 | if (tty_paranoia_check(tty, inode, "tty_read")) |
967 | return -EIO; | |
968 | if (!tty || (test_bit(TTY_IO_ERROR, &tty->flags))) | |
969 | return -EIO; | |
970 | ||
971 | /* We want to wait for the line discipline to sort out in this | |
972 | situation */ | |
973 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
974 | if (ld->ops->read) |
975 | i = (ld->ops->read)(tty, file, buf, count); | |
1da177e4 LT |
976 | else |
977 | i = -EIO; | |
978 | tty_ldisc_deref(ld); | |
1da177e4 LT |
979 | if (i > 0) |
980 | inode->i_atime = current_fs_time(inode->i_sb); | |
981 | return i; | |
982 | } | |
983 | ||
9c1729db | 984 | void tty_write_unlock(struct tty_struct *tty) |
83c67571 | 985 | __releases(&tty->atomic_write_lock) |
9c1729db AC |
986 | { |
987 | mutex_unlock(&tty->atomic_write_lock); | |
4b19449d | 988 | wake_up_interruptible_poll(&tty->write_wait, POLLOUT); |
9c1729db AC |
989 | } |
990 | ||
991 | int tty_write_lock(struct tty_struct *tty, int ndelay) | |
83c67571 | 992 | __acquires(&tty->atomic_write_lock) |
9c1729db AC |
993 | { |
994 | if (!mutex_trylock(&tty->atomic_write_lock)) { | |
995 | if (ndelay) | |
996 | return -EAGAIN; | |
997 | if (mutex_lock_interruptible(&tty->atomic_write_lock)) | |
998 | return -ERESTARTSYS; | |
999 | } | |
1000 | return 0; | |
1001 | } | |
1002 | ||
1da177e4 LT |
1003 | /* |
1004 | * Split writes up in sane blocksizes to avoid | |
1005 | * denial-of-service type attacks | |
1006 | */ | |
1007 | static inline ssize_t do_tty_write( | |
1008 | ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), | |
1009 | struct tty_struct *tty, | |
1010 | struct file *file, | |
1011 | const char __user *buf, | |
1012 | size_t count) | |
1013 | { | |
9c1729db | 1014 | ssize_t ret, written = 0; |
1da177e4 | 1015 | unsigned int chunk; |
37bdfb07 | 1016 | |
9c1729db AC |
1017 | ret = tty_write_lock(tty, file->f_flags & O_NDELAY); |
1018 | if (ret < 0) | |
1019 | return ret; | |
1da177e4 LT |
1020 | |
1021 | /* | |
1022 | * We chunk up writes into a temporary buffer. This | |
1023 | * simplifies low-level drivers immensely, since they | |
1024 | * don't have locking issues and user mode accesses. | |
1025 | * | |
1026 | * But if TTY_NO_WRITE_SPLIT is set, we should use a | |
1027 | * big chunk-size.. | |
1028 | * | |
1029 | * The default chunk-size is 2kB, because the NTTY | |
1030 | * layer has problems with bigger chunks. It will | |
1031 | * claim to be able to handle more characters than | |
1032 | * it actually does. | |
af9b897e AC |
1033 | * |
1034 | * FIXME: This can probably go away now except that 64K chunks | |
1035 | * are too likely to fail unless switched to vmalloc... | |
1da177e4 LT |
1036 | */ |
1037 | chunk = 2048; | |
1038 | if (test_bit(TTY_NO_WRITE_SPLIT, &tty->flags)) | |
1039 | chunk = 65536; | |
1040 | if (count < chunk) | |
1041 | chunk = count; | |
1042 | ||
70522e12 | 1043 | /* write_buf/write_cnt is protected by the atomic_write_lock mutex */ |
1da177e4 | 1044 | if (tty->write_cnt < chunk) { |
402fda92 | 1045 | unsigned char *buf_chunk; |
1da177e4 LT |
1046 | |
1047 | if (chunk < 1024) | |
1048 | chunk = 1024; | |
1049 | ||
402fda92 JW |
1050 | buf_chunk = kmalloc(chunk, GFP_KERNEL); |
1051 | if (!buf_chunk) { | |
9c1729db AC |
1052 | ret = -ENOMEM; |
1053 | goto out; | |
1da177e4 LT |
1054 | } |
1055 | kfree(tty->write_buf); | |
1056 | tty->write_cnt = chunk; | |
402fda92 | 1057 | tty->write_buf = buf_chunk; |
1da177e4 LT |
1058 | } |
1059 | ||
1060 | /* Do the write .. */ | |
1061 | for (;;) { | |
1062 | size_t size = count; | |
1063 | if (size > chunk) | |
1064 | size = chunk; | |
1065 | ret = -EFAULT; | |
1066 | if (copy_from_user(tty->write_buf, buf, size)) | |
1067 | break; | |
1da177e4 | 1068 | ret = write(tty, file, tty->write_buf, size); |
1da177e4 LT |
1069 | if (ret <= 0) |
1070 | break; | |
1071 | written += ret; | |
1072 | buf += ret; | |
1073 | count -= ret; | |
1074 | if (!count) | |
1075 | break; | |
1076 | ret = -ERESTARTSYS; | |
1077 | if (signal_pending(current)) | |
1078 | break; | |
1079 | cond_resched(); | |
1080 | } | |
1081 | if (written) { | |
a7113a96 | 1082 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
1083 | inode->i_mtime = current_fs_time(inode->i_sb); |
1084 | ret = written; | |
1085 | } | |
9c1729db AC |
1086 | out: |
1087 | tty_write_unlock(tty); | |
1da177e4 LT |
1088 | return ret; |
1089 | } | |
1090 | ||
95f9bfc6 AC |
1091 | /** |
1092 | * tty_write_message - write a message to a certain tty, not just the console. | |
1093 | * @tty: the destination tty_struct | |
1094 | * @msg: the message to write | |
1095 | * | |
1096 | * This is used for messages that need to be redirected to a specific tty. | |
1097 | * We don't put it into the syslog queue right now maybe in the future if | |
1098 | * really needed. | |
1099 | * | |
ec79d605 | 1100 | * We must still hold the BTM and test the CLOSING flag for the moment. |
95f9bfc6 AC |
1101 | */ |
1102 | ||
1103 | void tty_write_message(struct tty_struct *tty, char *msg) | |
1104 | { | |
95f9bfc6 AC |
1105 | if (tty) { |
1106 | mutex_lock(&tty->atomic_write_lock); | |
d29f3ef3 | 1107 | tty_lock(tty); |
eeb89d91 | 1108 | if (tty->ops->write && !test_bit(TTY_CLOSING, &tty->flags)) { |
d29f3ef3 | 1109 | tty_unlock(tty); |
95f9bfc6 | 1110 | tty->ops->write(tty, msg, strlen(msg)); |
eeb89d91 | 1111 | } else |
d29f3ef3 | 1112 | tty_unlock(tty); |
95f9bfc6 AC |
1113 | tty_write_unlock(tty); |
1114 | } | |
95f9bfc6 AC |
1115 | return; |
1116 | } | |
1117 | ||
1da177e4 | 1118 | |
af9b897e AC |
1119 | /** |
1120 | * tty_write - write method for tty device file | |
1121 | * @file: tty file pointer | |
1122 | * @buf: user data to write | |
1123 | * @count: bytes to write | |
1124 | * @ppos: unused | |
1125 | * | |
1126 | * Write data to a tty device via the line discipline. | |
1127 | * | |
1128 | * Locking: | |
1129 | * Locks the line discipline as required | |
1130 | * Writes to the tty driver are serialized by the atomic_write_lock | |
1131 | * and are then processed in chunks to the device. The line discipline | |
a88a69c9 | 1132 | * write method will not be invoked in parallel for each device. |
af9b897e AC |
1133 | */ |
1134 | ||
37bdfb07 AC |
1135 | static ssize_t tty_write(struct file *file, const char __user *buf, |
1136 | size_t count, loff_t *ppos) | |
1da177e4 | 1137 | { |
a7113a96 | 1138 | struct inode *inode = file->f_path.dentry->d_inode; |
d996b62a NP |
1139 | struct tty_struct *tty = file_tty(file); |
1140 | struct tty_ldisc *ld; | |
1da177e4 | 1141 | ssize_t ret; |
37bdfb07 | 1142 | |
1da177e4 LT |
1143 | if (tty_paranoia_check(tty, inode, "tty_write")) |
1144 | return -EIO; | |
f34d7a5b | 1145 | if (!tty || !tty->ops->write || |
37bdfb07 AC |
1146 | (test_bit(TTY_IO_ERROR, &tty->flags))) |
1147 | return -EIO; | |
f34d7a5b AC |
1148 | /* Short term debug to catch buggy drivers */ |
1149 | if (tty->ops->write_room == NULL) | |
1150 | printk(KERN_ERR "tty driver %s lacks a write_room method.\n", | |
1151 | tty->driver->name); | |
37bdfb07 | 1152 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 1153 | if (!ld->ops->write) |
1da177e4 LT |
1154 | ret = -EIO; |
1155 | else | |
a352def2 | 1156 | ret = do_tty_write(ld->ops->write, tty, file, buf, count); |
1da177e4 LT |
1157 | tty_ldisc_deref(ld); |
1158 | return ret; | |
1159 | } | |
1160 | ||
37bdfb07 AC |
1161 | ssize_t redirected_tty_write(struct file *file, const char __user *buf, |
1162 | size_t count, loff_t *ppos) | |
1da177e4 LT |
1163 | { |
1164 | struct file *p = NULL; | |
1165 | ||
1166 | spin_lock(&redirect_lock); | |
1167 | if (redirect) { | |
1168 | get_file(redirect); | |
1169 | p = redirect; | |
1170 | } | |
1171 | spin_unlock(&redirect_lock); | |
1172 | ||
1173 | if (p) { | |
1174 | ssize_t res; | |
1175 | res = vfs_write(p, buf, count, &p->f_pos); | |
1176 | fput(p); | |
1177 | return res; | |
1178 | } | |
1da177e4 LT |
1179 | return tty_write(file, buf, count, ppos); |
1180 | } | |
1181 | ||
1182 | static char ptychar[] = "pqrstuvwxyzabcde"; | |
1183 | ||
af9b897e AC |
1184 | /** |
1185 | * pty_line_name - generate name for a pty | |
1186 | * @driver: the tty driver in use | |
1187 | * @index: the minor number | |
1188 | * @p: output buffer of at least 6 bytes | |
1189 | * | |
1190 | * Generate a name from a driver reference and write it to the output | |
1191 | * buffer. | |
1192 | * | |
1193 | * Locking: None | |
1194 | */ | |
1195 | static void pty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1196 | { |
1197 | int i = index + driver->name_base; | |
1198 | /* ->name is initialized to "ttyp", but "tty" is expected */ | |
1199 | sprintf(p, "%s%c%x", | |
37bdfb07 AC |
1200 | driver->subtype == PTY_TYPE_SLAVE ? "tty" : driver->name, |
1201 | ptychar[i >> 4 & 0xf], i & 0xf); | |
1da177e4 LT |
1202 | } |
1203 | ||
af9b897e | 1204 | /** |
8b0a88d5 | 1205 | * tty_line_name - generate name for a tty |
af9b897e AC |
1206 | * @driver: the tty driver in use |
1207 | * @index: the minor number | |
1208 | * @p: output buffer of at least 7 bytes | |
1209 | * | |
1210 | * Generate a name from a driver reference and write it to the output | |
1211 | * buffer. | |
1212 | * | |
1213 | * Locking: None | |
1214 | */ | |
1215 | static void tty_line_name(struct tty_driver *driver, int index, char *p) | |
1da177e4 LT |
1216 | { |
1217 | sprintf(p, "%s%d", driver->name, index + driver->name_base); | |
1218 | } | |
1219 | ||
99f1fe18 AC |
1220 | /** |
1221 | * tty_driver_lookup_tty() - find an existing tty, if any | |
1222 | * @driver: the driver for the tty | |
1223 | * @idx: the minor number | |
23499705 | 1224 | * |
99f1fe18 | 1225 | * Return the tty, if found or ERR_PTR() otherwise. |
23499705 | 1226 | * |
99f1fe18 AC |
1227 | * Locking: tty_mutex must be held. If tty is found, the mutex must |
1228 | * be held until the 'fast-open' is also done. Will change once we | |
1229 | * have refcounting in the driver and per driver locking | |
23499705 | 1230 | */ |
a47d545f | 1231 | static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, |
15f1a633 | 1232 | struct inode *inode, int idx) |
23499705 | 1233 | { |
99f1fe18 | 1234 | if (driver->ops->lookup) |
15f1a633 | 1235 | return driver->ops->lookup(driver, inode, idx); |
23499705 | 1236 | |
d4834267 | 1237 | return driver->ttys[idx]; |
23499705 SB |
1238 | } |
1239 | ||
bf970ee4 AC |
1240 | /** |
1241 | * tty_init_termios - helper for termios setup | |
1242 | * @tty: the tty to set up | |
1243 | * | |
1244 | * Initialise the termios structures for this tty. Thus runs under | |
1245 | * the tty_mutex currently so we can be relaxed about ordering. | |
1246 | */ | |
1247 | ||
1248 | int tty_init_termios(struct tty_struct *tty) | |
1249 | { | |
fe6e29fd | 1250 | struct ktermios *tp; |
bf970ee4 AC |
1251 | int idx = tty->index; |
1252 | ||
1253 | tp = tty->driver->termios[idx]; | |
bf970ee4 | 1254 | if (tp == NULL) { |
fe6e29fd AC |
1255 | tp = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
1256 | if (tp == NULL) | |
bf970ee4 | 1257 | return -ENOMEM; |
bf970ee4 AC |
1258 | memcpy(tp, &tty->driver->init_termios, |
1259 | sizeof(struct ktermios)); | |
1260 | tty->driver->termios[idx] = tp; | |
bf970ee4 AC |
1261 | } |
1262 | tty->termios = tp; | |
fe6e29fd | 1263 | tty->termios_locked = tp + 1; |
bf970ee4 AC |
1264 | |
1265 | /* Compatibility until drivers always set this */ | |
1266 | tty->termios->c_ispeed = tty_termios_input_baud_rate(tty->termios); | |
1267 | tty->termios->c_ospeed = tty_termios_baud_rate(tty->termios); | |
1268 | return 0; | |
1269 | } | |
fe1ae7fd | 1270 | EXPORT_SYMBOL_GPL(tty_init_termios); |
bf970ee4 | 1271 | |
66d450e8 JS |
1272 | int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty) |
1273 | { | |
1274 | int ret = tty_init_termios(tty); | |
1275 | if (ret) | |
1276 | return ret; | |
1277 | ||
1278 | tty_driver_kref_get(driver); | |
1279 | tty->count++; | |
1280 | driver->ttys[tty->index] = tty; | |
1281 | return 0; | |
1282 | } | |
1283 | EXPORT_SYMBOL_GPL(tty_standard_install); | |
1284 | ||
99f1fe18 | 1285 | /** |
8b0a88d5 AC |
1286 | * tty_driver_install_tty() - install a tty entry in the driver |
1287 | * @driver: the driver for the tty | |
1288 | * @tty: the tty | |
1289 | * | |
1290 | * Install a tty object into the driver tables. The tty->index field | |
bf970ee4 AC |
1291 | * will be set by the time this is called. This method is responsible |
1292 | * for ensuring any need additional structures are allocated and | |
1293 | * configured. | |
8b0a88d5 AC |
1294 | * |
1295 | * Locking: tty_mutex for now | |
1296 | */ | |
1297 | static int tty_driver_install_tty(struct tty_driver *driver, | |
1298 | struct tty_struct *tty) | |
1299 | { | |
66d450e8 JS |
1300 | return driver->ops->install ? driver->ops->install(driver, tty) : |
1301 | tty_standard_install(driver, tty); | |
8b0a88d5 AC |
1302 | } |
1303 | ||
1304 | /** | |
1305 | * tty_driver_remove_tty() - remove a tty from the driver tables | |
1306 | * @driver: the driver for the tty | |
1307 | * @idx: the minor number | |
1308 | * | |
1309 | * Remvoe a tty object from the driver tables. The tty->index field | |
1310 | * will be set by the time this is called. | |
1311 | * | |
1312 | * Locking: tty_mutex for now | |
1313 | */ | |
24d406a6 | 1314 | void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
1315 | { |
1316 | if (driver->ops->remove) | |
1317 | driver->ops->remove(driver, tty); | |
1318 | else | |
1319 | driver->ttys[tty->index] = NULL; | |
1320 | } | |
1321 | ||
1322 | /* | |
1323 | * tty_reopen() - fast re-open of an open tty | |
1324 | * @tty - the tty to open | |
23499705 | 1325 | * |
99f1fe18 | 1326 | * Return 0 on success, -errno on error. |
23499705 | 1327 | * |
99f1fe18 AC |
1328 | * Locking: tty_mutex must be held from the time the tty was found |
1329 | * till this open completes. | |
23499705 | 1330 | */ |
99f1fe18 | 1331 | static int tty_reopen(struct tty_struct *tty) |
23499705 SB |
1332 | { |
1333 | struct tty_driver *driver = tty->driver; | |
1334 | ||
e2efafbf | 1335 | if (test_bit(TTY_CLOSING, &tty->flags) || |
acfa747b | 1336 | test_bit(TTY_HUPPING, &tty->flags) || |
e2efafbf | 1337 | test_bit(TTY_LDISC_CHANGING, &tty->flags)) |
23499705 SB |
1338 | return -EIO; |
1339 | ||
1340 | if (driver->type == TTY_DRIVER_TYPE_PTY && | |
1341 | driver->subtype == PTY_TYPE_MASTER) { | |
1342 | /* | |
1343 | * special case for PTY masters: only one open permitted, | |
1344 | * and the slave side open count is incremented as well. | |
1345 | */ | |
1346 | if (tty->count) | |
1347 | return -EIO; | |
1348 | ||
1349 | tty->link->count++; | |
1350 | } | |
1351 | tty->count++; | |
23499705 | 1352 | |
1aa4bed8 | 1353 | mutex_lock(&tty->ldisc_mutex); |
99f1fe18 | 1354 | WARN_ON(!test_bit(TTY_LDISC, &tty->flags)); |
1aa4bed8 | 1355 | mutex_unlock(&tty->ldisc_mutex); |
23499705 SB |
1356 | |
1357 | return 0; | |
1358 | } | |
1359 | ||
af9b897e | 1360 | /** |
d81ed103 | 1361 | * tty_init_dev - initialise a tty device |
af9b897e AC |
1362 | * @driver: tty driver we are opening a device on |
1363 | * @idx: device index | |
15582d36 | 1364 | * @ret_tty: returned tty structure |
af9b897e AC |
1365 | * |
1366 | * Prepare a tty device. This may not be a "new" clean device but | |
1367 | * could also be an active device. The pty drivers require special | |
1368 | * handling because of this. | |
1369 | * | |
1370 | * Locking: | |
1371 | * The function is called under the tty_mutex, which | |
1372 | * protects us from the tty struct or driver itself going away. | |
1373 | * | |
1374 | * On exit the tty device has the line discipline attached and | |
1375 | * a reference count of 1. If a pair was created for pty/tty use | |
1376 | * and the other was a pty master then it too has a reference count of 1. | |
1377 | * | |
1da177e4 | 1378 | * WSH 06/09/97: Rewritten to remove races and properly clean up after a |
70522e12 IM |
1379 | * failed open. The new code protects the open with a mutex, so it's |
1380 | * really quite straightforward. The mutex locking can probably be | |
1da177e4 LT |
1381 | * relaxed for the (most common) case of reopening a tty. |
1382 | */ | |
af9b897e | 1383 | |
593a27c4 | 1384 | struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx) |
1da177e4 | 1385 | { |
bf970ee4 | 1386 | struct tty_struct *tty; |
73ec06fc | 1387 | int retval; |
1da177e4 | 1388 | |
1da177e4 LT |
1389 | /* |
1390 | * First time open is complex, especially for PTY devices. | |
1391 | * This code guarantees that either everything succeeds and the | |
1392 | * TTY is ready for operation, or else the table slots are vacated | |
37bdfb07 | 1393 | * and the allocated memory released. (Except that the termios |
1da177e4 LT |
1394 | * and locked termios may be retained.) |
1395 | */ | |
1396 | ||
73ec06fc AC |
1397 | if (!try_module_get(driver->owner)) |
1398 | return ERR_PTR(-ENODEV); | |
1da177e4 | 1399 | |
1da177e4 | 1400 | tty = alloc_tty_struct(); |
d5543503 JS |
1401 | if (!tty) { |
1402 | retval = -ENOMEM; | |
1403 | goto err_module_put; | |
1404 | } | |
bf970ee4 | 1405 | initialize_tty_struct(tty, driver, idx); |
1da177e4 | 1406 | |
d29f3ef3 | 1407 | tty_lock(tty); |
73ec06fc | 1408 | retval = tty_driver_install_tty(driver, tty); |
d5543503 | 1409 | if (retval < 0) |
a9dccddb | 1410 | goto err_deinit_tty; |
8b0a88d5 | 1411 | |
37bdfb07 | 1412 | /* |
1da177e4 | 1413 | * Structures all installed ... call the ldisc open routines. |
d5698c28 CH |
1414 | * If we fail here just call release_tty to clean up. No need |
1415 | * to decrement the use counts, as release_tty doesn't care. | |
1da177e4 | 1416 | */ |
bf970ee4 | 1417 | retval = tty_ldisc_setup(tty, tty->link); |
01e1abb2 | 1418 | if (retval) |
d5543503 | 1419 | goto err_release_tty; |
d29f3ef3 | 1420 | /* Return the tty locked so that it cannot vanish under the caller */ |
73ec06fc | 1421 | return tty; |
1da177e4 | 1422 | |
a9dccddb | 1423 | err_deinit_tty: |
d29f3ef3 | 1424 | tty_unlock(tty); |
a9dccddb | 1425 | deinitialize_tty_struct(tty); |
d5543503 JS |
1426 | free_tty_struct(tty); |
1427 | err_module_put: | |
1da177e4 | 1428 | module_put(driver->owner); |
d5543503 | 1429 | return ERR_PTR(retval); |
1da177e4 | 1430 | |
d5698c28 | 1431 | /* call the tty release_tty routine to clean out this slot */ |
d5543503 | 1432 | err_release_tty: |
d29f3ef3 | 1433 | tty_unlock(tty); |
5a3c6b25 | 1434 | printk_ratelimited(KERN_INFO "tty_init_dev: ldisc open failed, " |
4050914f | 1435 | "clearing slot %d\n", idx); |
d5698c28 | 1436 | release_tty(tty, idx); |
73ec06fc | 1437 | return ERR_PTR(retval); |
1da177e4 LT |
1438 | } |
1439 | ||
feebed65 AC |
1440 | void tty_free_termios(struct tty_struct *tty) |
1441 | { | |
1442 | struct ktermios *tp; | |
1443 | int idx = tty->index; | |
1444 | /* Kill this flag and push into drivers for locking etc */ | |
1445 | if (tty->driver->flags & TTY_DRIVER_RESET_TERMIOS) { | |
1446 | /* FIXME: Locking on ->termios array */ | |
1447 | tp = tty->termios; | |
1448 | tty->driver->termios[idx] = NULL; | |
1449 | kfree(tp); | |
feebed65 AC |
1450 | } |
1451 | } | |
1452 | EXPORT_SYMBOL(tty_free_termios); | |
1453 | ||
1454 | void tty_shutdown(struct tty_struct *tty) | |
1455 | { | |
8b0a88d5 | 1456 | tty_driver_remove_tty(tty->driver, tty); |
feebed65 AC |
1457 | tty_free_termios(tty); |
1458 | } | |
1459 | EXPORT_SYMBOL(tty_shutdown); | |
1460 | ||
af9b897e | 1461 | /** |
d5698c28 | 1462 | * release_one_tty - release tty structure memory |
9c9f4ded | 1463 | * @kref: kref of tty we are obliterating |
af9b897e AC |
1464 | * |
1465 | * Releases memory associated with a tty structure, and clears out the | |
1466 | * driver table slots. This function is called when a device is no longer | |
1467 | * in use. It also gets called when setup of a device fails. | |
1468 | * | |
1469 | * Locking: | |
1470 | * tty_mutex - sometimes only | |
1471 | * takes the file list lock internally when working on the list | |
1472 | * of ttys that the driver keeps. | |
b50989dc AC |
1473 | * |
1474 | * This method gets called from a work queue so that the driver private | |
f278a2f7 | 1475 | * cleanup ops can sleep (needed for USB at least) |
1da177e4 | 1476 | */ |
b50989dc | 1477 | static void release_one_tty(struct work_struct *work) |
1da177e4 | 1478 | { |
b50989dc AC |
1479 | struct tty_struct *tty = |
1480 | container_of(work, struct tty_struct, hangup_work); | |
6f967f78 | 1481 | struct tty_driver *driver = tty->driver; |
d5698c28 | 1482 | |
f278a2f7 DY |
1483 | if (tty->ops->cleanup) |
1484 | tty->ops->cleanup(tty); | |
1485 | ||
1da177e4 | 1486 | tty->magic = 0; |
7d7b93c1 | 1487 | tty_driver_kref_put(driver); |
6f967f78 | 1488 | module_put(driver->owner); |
d5698c28 | 1489 | |
ee2ffa0d | 1490 | spin_lock(&tty_files_lock); |
1da177e4 | 1491 | list_del_init(&tty->tty_files); |
ee2ffa0d | 1492 | spin_unlock(&tty_files_lock); |
d5698c28 | 1493 | |
6da8d866 ON |
1494 | put_pid(tty->pgrp); |
1495 | put_pid(tty->session); | |
1da177e4 LT |
1496 | free_tty_struct(tty); |
1497 | } | |
1498 | ||
b50989dc AC |
1499 | static void queue_release_one_tty(struct kref *kref) |
1500 | { | |
1501 | struct tty_struct *tty = container_of(kref, struct tty_struct, kref); | |
f278a2f7 DY |
1502 | |
1503 | if (tty->ops->shutdown) | |
1504 | tty->ops->shutdown(tty); | |
1505 | else | |
1506 | tty_shutdown(tty); | |
1507 | ||
b50989dc AC |
1508 | /* The hangup queue is now free so we can reuse it rather than |
1509 | waste a chunk of memory for each port */ | |
1510 | INIT_WORK(&tty->hangup_work, release_one_tty); | |
1511 | schedule_work(&tty->hangup_work); | |
1512 | } | |
1513 | ||
9c9f4ded AC |
1514 | /** |
1515 | * tty_kref_put - release a tty kref | |
1516 | * @tty: tty device | |
1517 | * | |
1518 | * Release a reference to a tty device and if need be let the kref | |
1519 | * layer destruct the object for us | |
1520 | */ | |
1521 | ||
1522 | void tty_kref_put(struct tty_struct *tty) | |
1523 | { | |
1524 | if (tty) | |
b50989dc | 1525 | kref_put(&tty->kref, queue_release_one_tty); |
9c9f4ded AC |
1526 | } |
1527 | EXPORT_SYMBOL(tty_kref_put); | |
1528 | ||
d5698c28 CH |
1529 | /** |
1530 | * release_tty - release tty structure memory | |
1531 | * | |
1532 | * Release both @tty and a possible linked partner (think pty pair), | |
1533 | * and decrement the refcount of the backing module. | |
1534 | * | |
1535 | * Locking: | |
1536 | * tty_mutex - sometimes only | |
1537 | * takes the file list lock internally when working on the list | |
1538 | * of ttys that the driver keeps. | |
1539 | * FIXME: should we require tty_mutex is held here ?? | |
9c9f4ded | 1540 | * |
d5698c28 CH |
1541 | */ |
1542 | static void release_tty(struct tty_struct *tty, int idx) | |
1543 | { | |
9c9f4ded AC |
1544 | /* This should always be true but check for the moment */ |
1545 | WARN_ON(tty->index != idx); | |
1546 | ||
d5698c28 | 1547 | if (tty->link) |
9c9f4ded AC |
1548 | tty_kref_put(tty->link); |
1549 | tty_kref_put(tty); | |
d5698c28 CH |
1550 | } |
1551 | ||
955787ca JS |
1552 | /** |
1553 | * tty_release_checks - check a tty before real release | |
1554 | * @tty: tty to check | |
1555 | * @o_tty: link of @tty (if any) | |
1556 | * @idx: index of the tty | |
1557 | * | |
1558 | * Performs some paranoid checking before true release of the @tty. | |
1559 | * This is a no-op unless TTY_PARANOIA_CHECK is defined. | |
1560 | */ | |
1561 | static int tty_release_checks(struct tty_struct *tty, struct tty_struct *o_tty, | |
1562 | int idx) | |
1563 | { | |
1564 | #ifdef TTY_PARANOIA_CHECK | |
1565 | if (idx < 0 || idx >= tty->driver->num) { | |
9de44bd6 JS |
1566 | printk(KERN_DEBUG "%s: bad idx when trying to free (%s)\n", |
1567 | __func__, tty->name); | |
955787ca JS |
1568 | return -1; |
1569 | } | |
1570 | ||
1571 | /* not much to check for devpts */ | |
1572 | if (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) | |
1573 | return 0; | |
1574 | ||
1575 | if (tty != tty->driver->ttys[idx]) { | |
9de44bd6 JS |
1576 | printk(KERN_DEBUG "%s: driver.table[%d] not tty for (%s)\n", |
1577 | __func__, idx, tty->name); | |
955787ca JS |
1578 | return -1; |
1579 | } | |
1580 | if (tty->termios != tty->driver->termios[idx]) { | |
9de44bd6 JS |
1581 | printk(KERN_DEBUG "%s: driver.termios[%d] not termios for (%s)\n", |
1582 | __func__, idx, tty->name); | |
955787ca JS |
1583 | return -1; |
1584 | } | |
1585 | if (tty->driver->other) { | |
1586 | if (o_tty != tty->driver->other->ttys[idx]) { | |
9de44bd6 JS |
1587 | printk(KERN_DEBUG "%s: other->table[%d] not o_tty for (%s)\n", |
1588 | __func__, idx, tty->name); | |
955787ca JS |
1589 | return -1; |
1590 | } | |
1591 | if (o_tty->termios != tty->driver->other->termios[idx]) { | |
9de44bd6 JS |
1592 | printk(KERN_DEBUG "%s: other->termios[%d] not o_termios for (%s)\n", |
1593 | __func__, idx, tty->name); | |
955787ca JS |
1594 | return -1; |
1595 | } | |
1596 | if (o_tty->link != tty) { | |
9de44bd6 | 1597 | printk(KERN_DEBUG "%s: bad pty pointers\n", __func__); |
955787ca JS |
1598 | return -1; |
1599 | } | |
1600 | } | |
1601 | #endif | |
1602 | return 0; | |
1603 | } | |
1604 | ||
eeb89d91 AC |
1605 | /** |
1606 | * tty_release - vfs callback for close | |
1607 | * @inode: inode of tty | |
1608 | * @filp: file pointer for handle to tty | |
1609 | * | |
1610 | * Called the last time each file handle is closed that references | |
1611 | * this tty. There may however be several such references. | |
1612 | * | |
1613 | * Locking: | |
1614 | * Takes bkl. See tty_release_dev | |
1615 | * | |
1da177e4 LT |
1616 | * Even releasing the tty structures is a tricky business.. We have |
1617 | * to be very careful that the structures are all released at the | |
1618 | * same time, as interrupts might otherwise get the wrong pointers. | |
1619 | * | |
1620 | * WSH 09/09/97: rewritten to avoid some nasty race conditions that could | |
1621 | * lead to double frees or releasing memory still in use. | |
1622 | */ | |
eeb89d91 AC |
1623 | |
1624 | int tty_release(struct inode *inode, struct file *filp) | |
1da177e4 | 1625 | { |
d996b62a NP |
1626 | struct tty_struct *tty = file_tty(filp); |
1627 | struct tty_struct *o_tty; | |
1da177e4 | 1628 | int pty_master, tty_closing, o_tty_closing, do_sleep; |
14a6283e | 1629 | int devpts; |
1da177e4 LT |
1630 | int idx; |
1631 | char buf[64]; | |
37bdfb07 | 1632 | |
9de44bd6 | 1633 | if (tty_paranoia_check(tty, inode, __func__)) |
eeb89d91 | 1634 | return 0; |
1da177e4 | 1635 | |
d29f3ef3 | 1636 | tty_lock(tty); |
9de44bd6 | 1637 | check_tty_count(tty, __func__); |
1da177e4 | 1638 | |
ec79d605 | 1639 | __tty_fasync(-1, filp, 0); |
1da177e4 LT |
1640 | |
1641 | idx = tty->index; | |
1642 | pty_master = (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
1643 | tty->driver->subtype == PTY_TYPE_MASTER); | |
1644 | devpts = (tty->driver->flags & TTY_DRIVER_DEVPTS_MEM) != 0; | |
d29f3ef3 | 1645 | /* Review: parallel close */ |
1da177e4 LT |
1646 | o_tty = tty->link; |
1647 | ||
955787ca | 1648 | if (tty_release_checks(tty, o_tty, idx)) { |
d29f3ef3 | 1649 | tty_unlock(tty); |
eeb89d91 | 1650 | return 0; |
1da177e4 | 1651 | } |
1da177e4 LT |
1652 | |
1653 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1654 | printk(KERN_DEBUG "%s: %s (tty count=%d)...\n", __func__, |
1655 | tty_name(tty, buf), tty->count); | |
1da177e4 LT |
1656 | #endif |
1657 | ||
f34d7a5b AC |
1658 | if (tty->ops->close) |
1659 | tty->ops->close(tty, filp); | |
1da177e4 | 1660 | |
d29f3ef3 | 1661 | tty_unlock(tty); |
1da177e4 LT |
1662 | /* |
1663 | * Sanity check: if tty->count is going to zero, there shouldn't be | |
1664 | * any waiters on tty->read_wait or tty->write_wait. We test the | |
1665 | * wait queues and kick everyone out _before_ actually starting to | |
1666 | * close. This ensures that we won't block while releasing the tty | |
1667 | * structure. | |
1668 | * | |
1669 | * The test for the o_tty closing is necessary, since the master and | |
1670 | * slave sides may close in any order. If the slave side closes out | |
1671 | * first, its count will be one, since the master side holds an open. | |
1672 | * Thus this test wouldn't be triggered at the time the slave closes, | |
1673 | * so we do it now. | |
1674 | * | |
1675 | * Note that it's possible for the tty to be opened again while we're | |
1676 | * flushing out waiters. By recalculating the closing flags before | |
1677 | * each iteration we avoid any problems. | |
1678 | */ | |
1679 | while (1) { | |
1680 | /* Guard against races with tty->count changes elsewhere and | |
1681 | opens on /dev/tty */ | |
37bdfb07 | 1682 | |
70522e12 | 1683 | mutex_lock(&tty_mutex); |
d29f3ef3 | 1684 | tty_lock_pair(tty, o_tty); |
1da177e4 LT |
1685 | tty_closing = tty->count <= 1; |
1686 | o_tty_closing = o_tty && | |
1687 | (o_tty->count <= (pty_master ? 1 : 0)); | |
1da177e4 LT |
1688 | do_sleep = 0; |
1689 | ||
1690 | if (tty_closing) { | |
1691 | if (waitqueue_active(&tty->read_wait)) { | |
4b19449d | 1692 | wake_up_poll(&tty->read_wait, POLLIN); |
1da177e4 LT |
1693 | do_sleep++; |
1694 | } | |
1695 | if (waitqueue_active(&tty->write_wait)) { | |
4b19449d | 1696 | wake_up_poll(&tty->write_wait, POLLOUT); |
1da177e4 LT |
1697 | do_sleep++; |
1698 | } | |
1699 | } | |
1700 | if (o_tty_closing) { | |
1701 | if (waitqueue_active(&o_tty->read_wait)) { | |
4b19449d | 1702 | wake_up_poll(&o_tty->read_wait, POLLIN); |
1da177e4 LT |
1703 | do_sleep++; |
1704 | } | |
1705 | if (waitqueue_active(&o_tty->write_wait)) { | |
4b19449d | 1706 | wake_up_poll(&o_tty->write_wait, POLLOUT); |
1da177e4 LT |
1707 | do_sleep++; |
1708 | } | |
1709 | } | |
1710 | if (!do_sleep) | |
1711 | break; | |
1712 | ||
9de44bd6 JS |
1713 | printk(KERN_WARNING "%s: %s: read/write wait queue active!\n", |
1714 | __func__, tty_name(tty, buf)); | |
d29f3ef3 | 1715 | tty_unlock_pair(tty, o_tty); |
70522e12 | 1716 | mutex_unlock(&tty_mutex); |
1da177e4 | 1717 | schedule(); |
37bdfb07 | 1718 | } |
1da177e4 LT |
1719 | |
1720 | /* | |
37bdfb07 AC |
1721 | * The closing flags are now consistent with the open counts on |
1722 | * both sides, and we've completed the last operation that could | |
1da177e4 LT |
1723 | * block, so it's safe to proceed with closing. |
1724 | */ | |
1da177e4 LT |
1725 | if (pty_master) { |
1726 | if (--o_tty->count < 0) { | |
9de44bd6 JS |
1727 | printk(KERN_WARNING "%s: bad pty slave count (%d) for %s\n", |
1728 | __func__, o_tty->count, tty_name(o_tty, buf)); | |
1da177e4 LT |
1729 | o_tty->count = 0; |
1730 | } | |
1731 | } | |
1732 | if (--tty->count < 0) { | |
9de44bd6 JS |
1733 | printk(KERN_WARNING "%s: bad tty->count (%d) for %s\n", |
1734 | __func__, tty->count, tty_name(tty, buf)); | |
1da177e4 LT |
1735 | tty->count = 0; |
1736 | } | |
37bdfb07 | 1737 | |
1da177e4 LT |
1738 | /* |
1739 | * We've decremented tty->count, so we need to remove this file | |
1740 | * descriptor off the tty->tty_files list; this serves two | |
1741 | * purposes: | |
1742 | * - check_tty_count sees the correct number of file descriptors | |
1743 | * associated with this tty. | |
1744 | * - do_tty_hangup no longer sees this file descriptor as | |
1745 | * something that needs to be handled for hangups. | |
1746 | */ | |
d996b62a | 1747 | tty_del_file(filp); |
1da177e4 LT |
1748 | |
1749 | /* | |
1750 | * Perform some housekeeping before deciding whether to return. | |
1751 | * | |
1752 | * Set the TTY_CLOSING flag if this was the last open. In the | |
1753 | * case of a pty we may have to wait around for the other side | |
1754 | * to close, and TTY_CLOSING makes sure we can't be reopened. | |
1755 | */ | |
37bdfb07 | 1756 | if (tty_closing) |
1da177e4 | 1757 | set_bit(TTY_CLOSING, &tty->flags); |
37bdfb07 | 1758 | if (o_tty_closing) |
1da177e4 LT |
1759 | set_bit(TTY_CLOSING, &o_tty->flags); |
1760 | ||
1761 | /* | |
1762 | * If _either_ side is closing, make sure there aren't any | |
1763 | * processes that still think tty or o_tty is their controlling | |
1764 | * tty. | |
1765 | */ | |
1766 | if (tty_closing || o_tty_closing) { | |
1da177e4 | 1767 | read_lock(&tasklist_lock); |
24ec839c | 1768 | session_clear_tty(tty->session); |
1da177e4 | 1769 | if (o_tty) |
24ec839c | 1770 | session_clear_tty(o_tty->session); |
1da177e4 LT |
1771 | read_unlock(&tasklist_lock); |
1772 | } | |
1773 | ||
70522e12 | 1774 | mutex_unlock(&tty_mutex); |
da965822 | 1775 | |
1da177e4 | 1776 | /* check whether both sides are closing ... */ |
eeb89d91 | 1777 | if (!tty_closing || (o_tty && !o_tty_closing)) { |
d29f3ef3 | 1778 | tty_unlock_pair(tty, o_tty); |
eeb89d91 AC |
1779 | return 0; |
1780 | } | |
37bdfb07 | 1781 | |
1da177e4 | 1782 | #ifdef TTY_DEBUG_HANGUP |
9de44bd6 | 1783 | printk(KERN_DEBUG "%s: freeing tty structure...\n", __func__); |
1da177e4 LT |
1784 | #endif |
1785 | /* | |
01e1abb2 | 1786 | * Ask the line discipline code to release its structures |
1da177e4 | 1787 | */ |
01e1abb2 | 1788 | tty_ldisc_release(tty, o_tty); |
1da177e4 | 1789 | /* |
d5698c28 | 1790 | * The release_tty function takes care of the details of clearing |
d29f3ef3 AC |
1791 | * the slots and preserving the termios structure. The tty_unlock_pair |
1792 | * should be safe as we keep a kref while the tty is locked (so the | |
1793 | * unlock never unlocks a freed tty). | |
1da177e4 | 1794 | */ |
d5698c28 | 1795 | release_tty(tty, idx); |
d29f3ef3 | 1796 | tty_unlock_pair(tty, o_tty); |
1da177e4 | 1797 | |
1da177e4 | 1798 | /* Make this pty number available for reallocation */ |
718a9163 | 1799 | if (devpts) |
15f1a633 | 1800 | devpts_kill_index(inode, idx); |
eeb89d91 | 1801 | return 0; |
1da177e4 LT |
1802 | } |
1803 | ||
b82154ac JS |
1804 | /** |
1805 | * tty_open_current_tty - get tty of current task for open | |
1806 | * @device: device number | |
1807 | * @filp: file pointer to tty | |
1808 | * @return: tty of the current task iff @device is /dev/tty | |
1809 | * | |
1810 | * We cannot return driver and index like for the other nodes because | |
1811 | * devpts will not work then. It expects inodes to be from devpts FS. | |
3af502b9 AC |
1812 | * |
1813 | * We need to move to returning a refcounted object from all the lookup | |
1814 | * paths including this one. | |
b82154ac JS |
1815 | */ |
1816 | static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp) | |
1817 | { | |
1818 | struct tty_struct *tty; | |
1819 | ||
1820 | if (device != MKDEV(TTYAUX_MAJOR, 0)) | |
1821 | return NULL; | |
1822 | ||
1823 | tty = get_current_tty(); | |
1824 | if (!tty) | |
1825 | return ERR_PTR(-ENXIO); | |
1826 | ||
1827 | filp->f_flags |= O_NONBLOCK; /* Don't let /dev/tty block */ | |
1828 | /* noctty = 1; */ | |
1829 | tty_kref_put(tty); | |
1830 | /* FIXME: we put a reference and return a TTY! */ | |
3af502b9 | 1831 | /* This is only safe because the caller holds tty_mutex */ |
b82154ac JS |
1832 | return tty; |
1833 | } | |
1834 | ||
5b5e7040 JS |
1835 | /** |
1836 | * tty_lookup_driver - lookup a tty driver for a given device file | |
1837 | * @device: device number | |
1838 | * @filp: file pointer to tty | |
1839 | * @noctty: set if the device should not become a controlling tty | |
1840 | * @index: index for the device in the @return driver | |
1841 | * @return: driver for this inode (with increased refcount) | |
1842 | * | |
1843 | * If @return is not erroneous, the caller is responsible to decrement the | |
1844 | * refcount by tty_driver_kref_put. | |
1845 | * | |
1846 | * Locking: tty_mutex protects get_tty_driver | |
1847 | */ | |
1848 | static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp, | |
1849 | int *noctty, int *index) | |
1850 | { | |
1851 | struct tty_driver *driver; | |
1852 | ||
2cd0050c | 1853 | switch (device) { |
5b5e7040 | 1854 | #ifdef CONFIG_VT |
2cd0050c | 1855 | case MKDEV(TTY_MAJOR, 0): { |
5b5e7040 JS |
1856 | extern struct tty_driver *console_driver; |
1857 | driver = tty_driver_kref_get(console_driver); | |
1858 | *index = fg_console; | |
1859 | *noctty = 1; | |
2cd0050c | 1860 | break; |
5b5e7040 JS |
1861 | } |
1862 | #endif | |
2cd0050c | 1863 | case MKDEV(TTYAUX_MAJOR, 1): { |
5b5e7040 JS |
1864 | struct tty_driver *console_driver = console_device(index); |
1865 | if (console_driver) { | |
1866 | driver = tty_driver_kref_get(console_driver); | |
1867 | if (driver) { | |
1868 | /* Don't let /dev/console block */ | |
1869 | filp->f_flags |= O_NONBLOCK; | |
1870 | *noctty = 1; | |
2cd0050c | 1871 | break; |
5b5e7040 JS |
1872 | } |
1873 | } | |
1874 | return ERR_PTR(-ENODEV); | |
1875 | } | |
2cd0050c JS |
1876 | default: |
1877 | driver = get_tty_driver(device, index); | |
1878 | if (!driver) | |
1879 | return ERR_PTR(-ENODEV); | |
1880 | break; | |
1881 | } | |
5b5e7040 JS |
1882 | return driver; |
1883 | } | |
1884 | ||
af9b897e | 1885 | /** |
eeb89d91 | 1886 | * tty_open - open a tty device |
af9b897e AC |
1887 | * @inode: inode of device file |
1888 | * @filp: file pointer to tty | |
1da177e4 | 1889 | * |
af9b897e AC |
1890 | * tty_open and tty_release keep up the tty count that contains the |
1891 | * number of opens done on a tty. We cannot use the inode-count, as | |
1892 | * different inodes might point to the same tty. | |
1da177e4 | 1893 | * |
af9b897e AC |
1894 | * Open-counting is needed for pty masters, as well as for keeping |
1895 | * track of serial lines: DTR is dropped when the last close happens. | |
1896 | * (This is not done solely through tty->count, now. - Ted 1/27/92) | |
1897 | * | |
1898 | * The termios state of a pty is reset on first open so that | |
1899 | * settings don't persist across reuse. | |
1900 | * | |
5b5e7040 | 1901 | * Locking: tty_mutex protects tty, tty_lookup_driver and tty_init_dev. |
24ec839c PZ |
1902 | * tty->count should protect the rest. |
1903 | * ->siglock protects ->signal/->sighand | |
d29f3ef3 AC |
1904 | * |
1905 | * Note: the tty_unlock/lock cases without a ref are only safe due to | |
1906 | * tty_mutex | |
1da177e4 | 1907 | */ |
af9b897e | 1908 | |
eeb89d91 | 1909 | static int tty_open(struct inode *inode, struct file *filp) |
1da177e4 | 1910 | { |
b82154ac | 1911 | struct tty_struct *tty; |
1da177e4 | 1912 | int noctty, retval; |
b82154ac | 1913 | struct tty_driver *driver = NULL; |
1da177e4 LT |
1914 | int index; |
1915 | dev_t device = inode->i_rdev; | |
846c151a | 1916 | unsigned saved_flags = filp->f_flags; |
1da177e4 LT |
1917 | |
1918 | nonseekable_open(inode, filp); | |
37bdfb07 | 1919 | |
1da177e4 | 1920 | retry_open: |
fa90e1c9 JS |
1921 | retval = tty_alloc_file(filp); |
1922 | if (retval) | |
1923 | return -ENOMEM; | |
1924 | ||
1da177e4 LT |
1925 | noctty = filp->f_flags & O_NOCTTY; |
1926 | index = -1; | |
1927 | retval = 0; | |
37bdfb07 | 1928 | |
70522e12 | 1929 | mutex_lock(&tty_mutex); |
d29f3ef3 | 1930 | /* This is protected by the tty_mutex */ |
b82154ac JS |
1931 | tty = tty_open_current_tty(device, filp); |
1932 | if (IS_ERR(tty)) { | |
ba5db448 JS |
1933 | retval = PTR_ERR(tty); |
1934 | goto err_unlock; | |
5b5e7040 JS |
1935 | } else if (!tty) { |
1936 | driver = tty_lookup_driver(device, filp, &noctty, &index); | |
1937 | if (IS_ERR(driver)) { | |
ba5db448 JS |
1938 | retval = PTR_ERR(driver); |
1939 | goto err_unlock; | |
1da177e4 | 1940 | } |
1da177e4 | 1941 | |
4a2b5fdd | 1942 | /* check whether we're reopening an existing tty */ |
15f1a633 | 1943 | tty = tty_driver_lookup_tty(driver, inode, index); |
808ffa3d | 1944 | if (IS_ERR(tty)) { |
ba5db448 JS |
1945 | retval = PTR_ERR(tty); |
1946 | goto err_unlock; | |
808ffa3d | 1947 | } |
4a2b5fdd SB |
1948 | } |
1949 | ||
1950 | if (tty) { | |
d29f3ef3 | 1951 | tty_lock(tty); |
4a2b5fdd | 1952 | retval = tty_reopen(tty); |
d29f3ef3 AC |
1953 | if (retval < 0) { |
1954 | tty_unlock(tty); | |
4a2b5fdd | 1955 | tty = ERR_PTR(retval); |
d29f3ef3 AC |
1956 | } |
1957 | } else /* Returns with the tty_lock held for now */ | |
593a27c4 | 1958 | tty = tty_init_dev(driver, index); |
4a2b5fdd | 1959 | |
70522e12 | 1960 | mutex_unlock(&tty_mutex); |
b82154ac JS |
1961 | if (driver) |
1962 | tty_driver_kref_put(driver); | |
eeb89d91 | 1963 | if (IS_ERR(tty)) { |
ba5db448 JS |
1964 | retval = PTR_ERR(tty); |
1965 | goto err_file; | |
eeb89d91 | 1966 | } |
1da177e4 | 1967 | |
fa90e1c9 | 1968 | tty_add_file(tty, filp); |
d996b62a | 1969 | |
9de44bd6 | 1970 | check_tty_count(tty, __func__); |
1da177e4 LT |
1971 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && |
1972 | tty->driver->subtype == PTY_TYPE_MASTER) | |
1973 | noctty = 1; | |
1974 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 | 1975 | printk(KERN_DEBUG "%s: opening %s...\n", __func__, tty->name); |
1da177e4 | 1976 | #endif |
909bc774 HRK |
1977 | if (tty->ops->open) |
1978 | retval = tty->ops->open(tty, filp); | |
1979 | else | |
1980 | retval = -ENODEV; | |
1da177e4 LT |
1981 | filp->f_flags = saved_flags; |
1982 | ||
37bdfb07 AC |
1983 | if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) && |
1984 | !capable(CAP_SYS_ADMIN)) | |
1da177e4 LT |
1985 | retval = -EBUSY; |
1986 | ||
1987 | if (retval) { | |
1988 | #ifdef TTY_DEBUG_HANGUP | |
9de44bd6 JS |
1989 | printk(KERN_DEBUG "%s: error %d in opening %s...\n", __func__, |
1990 | retval, tty->name); | |
1da177e4 | 1991 | #endif |
d29f3ef3 | 1992 | tty_unlock(tty); /* need to call tty_release without BTM */ |
eeb89d91 | 1993 | tty_release(inode, filp); |
64ba3dc3 | 1994 | if (retval != -ERESTARTSYS) |
1da177e4 | 1995 | return retval; |
64ba3dc3 AB |
1996 | |
1997 | if (signal_pending(current)) | |
1da177e4 | 1998 | return retval; |
64ba3dc3 | 1999 | |
1da177e4 LT |
2000 | schedule(); |
2001 | /* | |
2002 | * Need to reset f_op in case a hangup happened. | |
2003 | */ | |
2004 | if (filp->f_op == &hung_up_tty_fops) | |
2005 | filp->f_op = &tty_fops; | |
2006 | goto retry_open; | |
2007 | } | |
d29f3ef3 | 2008 | tty_unlock(tty); |
eeb89d91 | 2009 | |
24ec839c PZ |
2010 | |
2011 | mutex_lock(&tty_mutex); | |
d29f3ef3 | 2012 | tty_lock(tty); |
24ec839c | 2013 | spin_lock_irq(¤t->sighand->siglock); |
1da177e4 LT |
2014 | if (!noctty && |
2015 | current->signal->leader && | |
2016 | !current->signal->tty && | |
ab521dc0 | 2017 | tty->session == NULL) |
2a65f1d9 | 2018 | __proc_set_tty(current, tty); |
24ec839c | 2019 | spin_unlock_irq(¤t->sighand->siglock); |
d29f3ef3 | 2020 | tty_unlock(tty); |
24ec839c | 2021 | mutex_unlock(&tty_mutex); |
1da177e4 | 2022 | return 0; |
ba5db448 | 2023 | err_unlock: |
ba5db448 JS |
2024 | mutex_unlock(&tty_mutex); |
2025 | /* after locks to avoid deadlock */ | |
2026 | if (!IS_ERR_OR_NULL(driver)) | |
2027 | tty_driver_kref_put(driver); | |
2028 | err_file: | |
2029 | tty_free_file(filp); | |
2030 | return retval; | |
1da177e4 LT |
2031 | } |
2032 | ||
39d95b9d JC |
2033 | |
2034 | ||
af9b897e AC |
2035 | /** |
2036 | * tty_poll - check tty status | |
2037 | * @filp: file being polled | |
2038 | * @wait: poll wait structures to update | |
2039 | * | |
2040 | * Call the line discipline polling method to obtain the poll | |
2041 | * status of the device. | |
2042 | * | |
2043 | * Locking: locks called line discipline but ldisc poll method | |
2044 | * may be re-entered freely by other callers. | |
2045 | */ | |
2046 | ||
37bdfb07 | 2047 | static unsigned int tty_poll(struct file *filp, poll_table *wait) |
1da177e4 | 2048 | { |
d996b62a | 2049 | struct tty_struct *tty = file_tty(filp); |
1da177e4 LT |
2050 | struct tty_ldisc *ld; |
2051 | int ret = 0; | |
2052 | ||
a7113a96 | 2053 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_poll")) |
1da177e4 | 2054 | return 0; |
37bdfb07 | 2055 | |
1da177e4 | 2056 | ld = tty_ldisc_ref_wait(tty); |
a352def2 AC |
2057 | if (ld->ops->poll) |
2058 | ret = (ld->ops->poll)(tty, filp, wait); | |
1da177e4 LT |
2059 | tty_ldisc_deref(ld); |
2060 | return ret; | |
2061 | } | |
2062 | ||
ec79d605 | 2063 | static int __tty_fasync(int fd, struct file *filp, int on) |
1da177e4 | 2064 | { |
d996b62a | 2065 | struct tty_struct *tty = file_tty(filp); |
47f86834 | 2066 | unsigned long flags; |
5d1e3230 | 2067 | int retval = 0; |
1da177e4 | 2068 | |
a7113a96 | 2069 | if (tty_paranoia_check(tty, filp->f_path.dentry->d_inode, "tty_fasync")) |
5d1e3230 | 2070 | goto out; |
37bdfb07 | 2071 | |
1da177e4 LT |
2072 | retval = fasync_helper(fd, filp, on, &tty->fasync); |
2073 | if (retval <= 0) | |
5d1e3230 | 2074 | goto out; |
1da177e4 LT |
2075 | |
2076 | if (on) { | |
ab521dc0 EB |
2077 | enum pid_type type; |
2078 | struct pid *pid; | |
1da177e4 LT |
2079 | if (!waitqueue_active(&tty->read_wait)) |
2080 | tty->minimum_to_wake = 1; | |
47f86834 | 2081 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2082 | if (tty->pgrp) { |
2083 | pid = tty->pgrp; | |
2084 | type = PIDTYPE_PGID; | |
2085 | } else { | |
2086 | pid = task_pid(current); | |
2087 | type = PIDTYPE_PID; | |
2088 | } | |
80e1e823 | 2089 | get_pid(pid); |
70362511 | 2090 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
80e1e823 LT |
2091 | retval = __f_setown(filp, pid, type, 0); |
2092 | put_pid(pid); | |
1da177e4 | 2093 | if (retval) |
5d1e3230 | 2094 | goto out; |
1da177e4 LT |
2095 | } else { |
2096 | if (!tty->fasync && !waitqueue_active(&tty->read_wait)) | |
2097 | tty->minimum_to_wake = N_TTY_BUF_SIZE; | |
2098 | } | |
5d1e3230 JC |
2099 | retval = 0; |
2100 | out: | |
ec79d605 AB |
2101 | return retval; |
2102 | } | |
2103 | ||
2104 | static int tty_fasync(int fd, struct file *filp, int on) | |
2105 | { | |
d29f3ef3 | 2106 | struct tty_struct *tty = file_tty(filp); |
ec79d605 | 2107 | int retval; |
d29f3ef3 AC |
2108 | |
2109 | tty_lock(tty); | |
ec79d605 | 2110 | retval = __tty_fasync(fd, filp, on); |
d29f3ef3 AC |
2111 | tty_unlock(tty); |
2112 | ||
5d1e3230 | 2113 | return retval; |
1da177e4 LT |
2114 | } |
2115 | ||
af9b897e AC |
2116 | /** |
2117 | * tiocsti - fake input character | |
2118 | * @tty: tty to fake input into | |
2119 | * @p: pointer to character | |
2120 | * | |
3a4fa0a2 | 2121 | * Fake input to a tty device. Does the necessary locking and |
af9b897e AC |
2122 | * input management. |
2123 | * | |
2124 | * FIXME: does not honour flow control ?? | |
2125 | * | |
2126 | * Locking: | |
2127 | * Called functions take tty_ldisc_lock | |
2128 | * current->signal->tty check is safe without locks | |
28298232 AC |
2129 | * |
2130 | * FIXME: may race normal receive processing | |
af9b897e AC |
2131 | */ |
2132 | ||
1da177e4 LT |
2133 | static int tiocsti(struct tty_struct *tty, char __user *p) |
2134 | { | |
2135 | char ch, mbz = 0; | |
2136 | struct tty_ldisc *ld; | |
37bdfb07 | 2137 | |
1da177e4 LT |
2138 | if ((current->signal->tty != tty) && !capable(CAP_SYS_ADMIN)) |
2139 | return -EPERM; | |
2140 | if (get_user(ch, p)) | |
2141 | return -EFAULT; | |
1e641743 | 2142 | tty_audit_tiocsti(tty, ch); |
1da177e4 | 2143 | ld = tty_ldisc_ref_wait(tty); |
a352def2 | 2144 | ld->ops->receive_buf(tty, &ch, &mbz, 1); |
1da177e4 LT |
2145 | tty_ldisc_deref(ld); |
2146 | return 0; | |
2147 | } | |
2148 | ||
af9b897e AC |
2149 | /** |
2150 | * tiocgwinsz - implement window query ioctl | |
2151 | * @tty; tty | |
2152 | * @arg: user buffer for result | |
2153 | * | |
808a0d38 | 2154 | * Copies the kernel idea of the window size into the user buffer. |
af9b897e | 2155 | * |
24ec839c | 2156 | * Locking: tty->termios_mutex is taken to ensure the winsize data |
808a0d38 | 2157 | * is consistent. |
af9b897e AC |
2158 | */ |
2159 | ||
37bdfb07 | 2160 | static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) |
1da177e4 | 2161 | { |
808a0d38 AC |
2162 | int err; |
2163 | ||
5785c95b | 2164 | mutex_lock(&tty->termios_mutex); |
808a0d38 | 2165 | err = copy_to_user(arg, &tty->winsize, sizeof(*arg)); |
5785c95b | 2166 | mutex_unlock(&tty->termios_mutex); |
808a0d38 AC |
2167 | |
2168 | return err ? -EFAULT: 0; | |
1da177e4 LT |
2169 | } |
2170 | ||
af9b897e | 2171 | /** |
8c9a9dd0 AC |
2172 | * tty_do_resize - resize event |
2173 | * @tty: tty being resized | |
8c9a9dd0 AC |
2174 | * @rows: rows (character) |
2175 | * @cols: cols (character) | |
2176 | * | |
3ad2f3fb | 2177 | * Update the termios variables and send the necessary signals to |
8c9a9dd0 | 2178 | * peform a terminal resize correctly |
af9b897e AC |
2179 | */ |
2180 | ||
fc6f6238 | 2181 | int tty_do_resize(struct tty_struct *tty, struct winsize *ws) |
1da177e4 | 2182 | { |
fc6f6238 | 2183 | struct pid *pgrp; |
47f86834 | 2184 | unsigned long flags; |
1da177e4 | 2185 | |
fc6f6238 AC |
2186 | /* Lock the tty */ |
2187 | mutex_lock(&tty->termios_mutex); | |
2188 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
ca9bda00 | 2189 | goto done; |
47f86834 AC |
2190 | /* Get the PID values and reference them so we can |
2191 | avoid holding the tty ctrl lock while sending signals */ | |
2192 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2193 | pgrp = get_pid(tty->pgrp); | |
47f86834 AC |
2194 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
2195 | ||
2196 | if (pgrp) | |
2197 | kill_pgrp(pgrp, SIGWINCH, 1); | |
47f86834 | 2198 | put_pid(pgrp); |
47f86834 | 2199 | |
8c9a9dd0 | 2200 | tty->winsize = *ws; |
ca9bda00 | 2201 | done: |
fc6f6238 | 2202 | mutex_unlock(&tty->termios_mutex); |
1da177e4 LT |
2203 | return 0; |
2204 | } | |
2205 | ||
8c9a9dd0 AC |
2206 | /** |
2207 | * tiocswinsz - implement window size set ioctl | |
fc6f6238 | 2208 | * @tty; tty side of tty |
8c9a9dd0 AC |
2209 | * @arg: user buffer for result |
2210 | * | |
2211 | * Copies the user idea of the window size to the kernel. Traditionally | |
2212 | * this is just advisory information but for the Linux console it | |
2213 | * actually has driver level meaning and triggers a VC resize. | |
2214 | * | |
2215 | * Locking: | |
25985edc | 2216 | * Driver dependent. The default do_resize method takes the |
8c9a9dd0 AC |
2217 | * tty termios mutex and ctrl_lock. The console takes its own lock |
2218 | * then calls into the default method. | |
2219 | */ | |
2220 | ||
fc6f6238 | 2221 | static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) |
8c9a9dd0 AC |
2222 | { |
2223 | struct winsize tmp_ws; | |
2224 | if (copy_from_user(&tmp_ws, arg, sizeof(*arg))) | |
2225 | return -EFAULT; | |
2226 | ||
2227 | if (tty->ops->resize) | |
fc6f6238 | 2228 | return tty->ops->resize(tty, &tmp_ws); |
8c9a9dd0 | 2229 | else |
fc6f6238 | 2230 | return tty_do_resize(tty, &tmp_ws); |
8c9a9dd0 AC |
2231 | } |
2232 | ||
af9b897e AC |
2233 | /** |
2234 | * tioccons - allow admin to move logical console | |
2235 | * @file: the file to become console | |
2236 | * | |
25985edc | 2237 | * Allow the administrator to move the redirected console device |
af9b897e AC |
2238 | * |
2239 | * Locking: uses redirect_lock to guard the redirect information | |
2240 | */ | |
2241 | ||
1da177e4 LT |
2242 | static int tioccons(struct file *file) |
2243 | { | |
2244 | if (!capable(CAP_SYS_ADMIN)) | |
2245 | return -EPERM; | |
2246 | if (file->f_op->write == redirected_tty_write) { | |
2247 | struct file *f; | |
2248 | spin_lock(&redirect_lock); | |
2249 | f = redirect; | |
2250 | redirect = NULL; | |
2251 | spin_unlock(&redirect_lock); | |
2252 | if (f) | |
2253 | fput(f); | |
2254 | return 0; | |
2255 | } | |
2256 | spin_lock(&redirect_lock); | |
2257 | if (redirect) { | |
2258 | spin_unlock(&redirect_lock); | |
2259 | return -EBUSY; | |
2260 | } | |
2261 | get_file(file); | |
2262 | redirect = file; | |
2263 | spin_unlock(&redirect_lock); | |
2264 | return 0; | |
2265 | } | |
2266 | ||
af9b897e AC |
2267 | /** |
2268 | * fionbio - non blocking ioctl | |
2269 | * @file: file to set blocking value | |
2270 | * @p: user parameter | |
2271 | * | |
2272 | * Historical tty interfaces had a blocking control ioctl before | |
2273 | * the generic functionality existed. This piece of history is preserved | |
2274 | * in the expected tty API of posix OS's. | |
2275 | * | |
6146b9af | 2276 | * Locking: none, the open file handle ensures it won't go away. |
af9b897e | 2277 | */ |
1da177e4 LT |
2278 | |
2279 | static int fionbio(struct file *file, int __user *p) | |
2280 | { | |
2281 | int nonblock; | |
2282 | ||
2283 | if (get_user(nonblock, p)) | |
2284 | return -EFAULT; | |
2285 | ||
db1dd4d3 | 2286 | spin_lock(&file->f_lock); |
1da177e4 LT |
2287 | if (nonblock) |
2288 | file->f_flags |= O_NONBLOCK; | |
2289 | else | |
2290 | file->f_flags &= ~O_NONBLOCK; | |
db1dd4d3 | 2291 | spin_unlock(&file->f_lock); |
1da177e4 LT |
2292 | return 0; |
2293 | } | |
2294 | ||
af9b897e AC |
2295 | /** |
2296 | * tiocsctty - set controlling tty | |
2297 | * @tty: tty structure | |
2298 | * @arg: user argument | |
2299 | * | |
2300 | * This ioctl is used to manage job control. It permits a session | |
2301 | * leader to set this tty as the controlling tty for the session. | |
2302 | * | |
2303 | * Locking: | |
28298232 | 2304 | * Takes tty_mutex() to protect tty instance |
24ec839c PZ |
2305 | * Takes tasklist_lock internally to walk sessions |
2306 | * Takes ->siglock() when updating signal->tty | |
af9b897e AC |
2307 | */ |
2308 | ||
1da177e4 LT |
2309 | static int tiocsctty(struct tty_struct *tty, int arg) |
2310 | { | |
24ec839c | 2311 | int ret = 0; |
ab521dc0 | 2312 | if (current->signal->leader && (task_session(current) == tty->session)) |
24ec839c PZ |
2313 | return ret; |
2314 | ||
2315 | mutex_lock(&tty_mutex); | |
1da177e4 LT |
2316 | /* |
2317 | * The process must be a session leader and | |
2318 | * not have a controlling tty already. | |
2319 | */ | |
24ec839c PZ |
2320 | if (!current->signal->leader || current->signal->tty) { |
2321 | ret = -EPERM; | |
2322 | goto unlock; | |
2323 | } | |
2324 | ||
ab521dc0 | 2325 | if (tty->session) { |
1da177e4 LT |
2326 | /* |
2327 | * This tty is already the controlling | |
2328 | * tty for another session group! | |
2329 | */ | |
37bdfb07 | 2330 | if (arg == 1 && capable(CAP_SYS_ADMIN)) { |
1da177e4 LT |
2331 | /* |
2332 | * Steal it away | |
2333 | */ | |
1da177e4 | 2334 | read_lock(&tasklist_lock); |
24ec839c | 2335 | session_clear_tty(tty->session); |
1da177e4 | 2336 | read_unlock(&tasklist_lock); |
24ec839c PZ |
2337 | } else { |
2338 | ret = -EPERM; | |
2339 | goto unlock; | |
2340 | } | |
1da177e4 | 2341 | } |
24ec839c PZ |
2342 | proc_set_tty(current, tty); |
2343 | unlock: | |
28298232 | 2344 | mutex_unlock(&tty_mutex); |
24ec839c | 2345 | return ret; |
1da177e4 LT |
2346 | } |
2347 | ||
5d0fdf1e AC |
2348 | /** |
2349 | * tty_get_pgrp - return a ref counted pgrp pid | |
2350 | * @tty: tty to read | |
2351 | * | |
2352 | * Returns a refcounted instance of the pid struct for the process | |
2353 | * group controlling the tty. | |
2354 | */ | |
2355 | ||
2356 | struct pid *tty_get_pgrp(struct tty_struct *tty) | |
2357 | { | |
2358 | unsigned long flags; | |
2359 | struct pid *pgrp; | |
2360 | ||
2361 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
2362 | pgrp = get_pid(tty->pgrp); | |
2363 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
2364 | ||
2365 | return pgrp; | |
2366 | } | |
2367 | EXPORT_SYMBOL_GPL(tty_get_pgrp); | |
2368 | ||
af9b897e AC |
2369 | /** |
2370 | * tiocgpgrp - get process group | |
2371 | * @tty: tty passed by user | |
25985edc | 2372 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2373 | * @p: returned pid |
2374 | * | |
2375 | * Obtain the process group of the tty. If there is no process group | |
2376 | * return an error. | |
2377 | * | |
24ec839c | 2378 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2379 | */ |
2380 | ||
1da177e4 LT |
2381 | static int tiocgpgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2382 | { | |
5d0fdf1e AC |
2383 | struct pid *pid; |
2384 | int ret; | |
1da177e4 LT |
2385 | /* |
2386 | * (tty == real_tty) is a cheap way of | |
2387 | * testing if the tty is NOT a master pty. | |
2388 | */ | |
2389 | if (tty == real_tty && current->signal->tty != real_tty) | |
2390 | return -ENOTTY; | |
5d0fdf1e AC |
2391 | pid = tty_get_pgrp(real_tty); |
2392 | ret = put_user(pid_vnr(pid), p); | |
2393 | put_pid(pid); | |
2394 | return ret; | |
1da177e4 LT |
2395 | } |
2396 | ||
af9b897e AC |
2397 | /** |
2398 | * tiocspgrp - attempt to set process group | |
2399 | * @tty: tty passed by user | |
2400 | * @real_tty: tty side device matching tty passed by user | |
2401 | * @p: pid pointer | |
2402 | * | |
2403 | * Set the process group of the tty to the session passed. Only | |
2404 | * permitted where the tty session is our session. | |
2405 | * | |
47f86834 | 2406 | * Locking: RCU, ctrl lock |
af9b897e AC |
2407 | */ |
2408 | ||
1da177e4 LT |
2409 | static int tiocspgrp(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2410 | { | |
04a2e6a5 EB |
2411 | struct pid *pgrp; |
2412 | pid_t pgrp_nr; | |
1da177e4 | 2413 | int retval = tty_check_change(real_tty); |
47f86834 | 2414 | unsigned long flags; |
1da177e4 LT |
2415 | |
2416 | if (retval == -EIO) | |
2417 | return -ENOTTY; | |
2418 | if (retval) | |
2419 | return retval; | |
2420 | if (!current->signal->tty || | |
2421 | (current->signal->tty != real_tty) || | |
ab521dc0 | 2422 | (real_tty->session != task_session(current))) |
1da177e4 | 2423 | return -ENOTTY; |
04a2e6a5 | 2424 | if (get_user(pgrp_nr, p)) |
1da177e4 | 2425 | return -EFAULT; |
04a2e6a5 | 2426 | if (pgrp_nr < 0) |
1da177e4 | 2427 | return -EINVAL; |
04a2e6a5 | 2428 | rcu_read_lock(); |
b488893a | 2429 | pgrp = find_vpid(pgrp_nr); |
04a2e6a5 EB |
2430 | retval = -ESRCH; |
2431 | if (!pgrp) | |
2432 | goto out_unlock; | |
2433 | retval = -EPERM; | |
2434 | if (session_of_pgrp(pgrp) != task_session(current)) | |
2435 | goto out_unlock; | |
2436 | retval = 0; | |
47f86834 | 2437 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
ab521dc0 EB |
2438 | put_pid(real_tty->pgrp); |
2439 | real_tty->pgrp = get_pid(pgrp); | |
47f86834 | 2440 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
04a2e6a5 EB |
2441 | out_unlock: |
2442 | rcu_read_unlock(); | |
2443 | return retval; | |
1da177e4 LT |
2444 | } |
2445 | ||
af9b897e AC |
2446 | /** |
2447 | * tiocgsid - get session id | |
2448 | * @tty: tty passed by user | |
25985edc | 2449 | * @real_tty: tty side of the tty passed by the user if a pty else the tty |
af9b897e AC |
2450 | * @p: pointer to returned session id |
2451 | * | |
2452 | * Obtain the session id of the tty. If there is no session | |
2453 | * return an error. | |
2454 | * | |
24ec839c | 2455 | * Locking: none. Reference to current->signal->tty is safe. |
af9b897e AC |
2456 | */ |
2457 | ||
1da177e4 LT |
2458 | static int tiocgsid(struct tty_struct *tty, struct tty_struct *real_tty, pid_t __user *p) |
2459 | { | |
2460 | /* | |
2461 | * (tty == real_tty) is a cheap way of | |
2462 | * testing if the tty is NOT a master pty. | |
2463 | */ | |
2464 | if (tty == real_tty && current->signal->tty != real_tty) | |
2465 | return -ENOTTY; | |
ab521dc0 | 2466 | if (!real_tty->session) |
1da177e4 | 2467 | return -ENOTTY; |
b488893a | 2468 | return put_user(pid_vnr(real_tty->session), p); |
1da177e4 LT |
2469 | } |
2470 | ||
af9b897e AC |
2471 | /** |
2472 | * tiocsetd - set line discipline | |
2473 | * @tty: tty device | |
2474 | * @p: pointer to user data | |
2475 | * | |
2476 | * Set the line discipline according to user request. | |
2477 | * | |
2478 | * Locking: see tty_set_ldisc, this function is just a helper | |
2479 | */ | |
2480 | ||
1da177e4 LT |
2481 | static int tiocsetd(struct tty_struct *tty, int __user *p) |
2482 | { | |
2483 | int ldisc; | |
04f378b1 | 2484 | int ret; |
1da177e4 LT |
2485 | |
2486 | if (get_user(ldisc, p)) | |
2487 | return -EFAULT; | |
04f378b1 | 2488 | |
04f378b1 | 2489 | ret = tty_set_ldisc(tty, ldisc); |
04f378b1 AC |
2490 | |
2491 | return ret; | |
1da177e4 LT |
2492 | } |
2493 | ||
af9b897e AC |
2494 | /** |
2495 | * send_break - performed time break | |
2496 | * @tty: device to break on | |
2497 | * @duration: timeout in mS | |
2498 | * | |
2499 | * Perform a timed break on hardware that lacks its own driver level | |
2500 | * timed break functionality. | |
2501 | * | |
2502 | * Locking: | |
28298232 | 2503 | * atomic_write_lock serializes |
af9b897e | 2504 | * |
af9b897e AC |
2505 | */ |
2506 | ||
b20f3ae5 | 2507 | static int send_break(struct tty_struct *tty, unsigned int duration) |
1da177e4 | 2508 | { |
9e98966c AC |
2509 | int retval; |
2510 | ||
2511 | if (tty->ops->break_ctl == NULL) | |
2512 | return 0; | |
2513 | ||
2514 | if (tty->driver->flags & TTY_DRIVER_HARDWARE_BREAK) | |
2515 | retval = tty->ops->break_ctl(tty, duration); | |
2516 | else { | |
2517 | /* Do the work ourselves */ | |
2518 | if (tty_write_lock(tty, 0) < 0) | |
2519 | return -EINTR; | |
2520 | retval = tty->ops->break_ctl(tty, -1); | |
2521 | if (retval) | |
2522 | goto out; | |
2523 | if (!signal_pending(current)) | |
2524 | msleep_interruptible(duration); | |
2525 | retval = tty->ops->break_ctl(tty, 0); | |
2526 | out: | |
2527 | tty_write_unlock(tty); | |
2528 | if (signal_pending(current)) | |
2529 | retval = -EINTR; | |
2530 | } | |
2531 | return retval; | |
1da177e4 LT |
2532 | } |
2533 | ||
af9b897e | 2534 | /** |
f34d7a5b | 2535 | * tty_tiocmget - get modem status |
af9b897e AC |
2536 | * @tty: tty device |
2537 | * @file: user file pointer | |
2538 | * @p: pointer to result | |
2539 | * | |
2540 | * Obtain the modem status bits from the tty driver if the feature | |
2541 | * is supported. Return -EINVAL if it is not available. | |
2542 | * | |
2543 | * Locking: none (up to the driver) | |
2544 | */ | |
2545 | ||
60b33c13 | 2546 | static int tty_tiocmget(struct tty_struct *tty, int __user *p) |
1da177e4 LT |
2547 | { |
2548 | int retval = -EINVAL; | |
2549 | ||
f34d7a5b | 2550 | if (tty->ops->tiocmget) { |
60b33c13 | 2551 | retval = tty->ops->tiocmget(tty); |
1da177e4 LT |
2552 | |
2553 | if (retval >= 0) | |
2554 | retval = put_user(retval, p); | |
2555 | } | |
2556 | return retval; | |
2557 | } | |
2558 | ||
af9b897e | 2559 | /** |
f34d7a5b | 2560 | * tty_tiocmset - set modem status |
af9b897e | 2561 | * @tty: tty device |
af9b897e AC |
2562 | * @cmd: command - clear bits, set bits or set all |
2563 | * @p: pointer to desired bits | |
2564 | * | |
2565 | * Set the modem status bits from the tty driver if the feature | |
2566 | * is supported. Return -EINVAL if it is not available. | |
2567 | * | |
2568 | * Locking: none (up to the driver) | |
2569 | */ | |
2570 | ||
20b9d177 | 2571 | static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, |
1da177e4 LT |
2572 | unsigned __user *p) |
2573 | { | |
ae677517 AC |
2574 | int retval; |
2575 | unsigned int set, clear, val; | |
1da177e4 | 2576 | |
ae677517 AC |
2577 | if (tty->ops->tiocmset == NULL) |
2578 | return -EINVAL; | |
1da177e4 | 2579 | |
ae677517 AC |
2580 | retval = get_user(val, p); |
2581 | if (retval) | |
2582 | return retval; | |
2583 | set = clear = 0; | |
2584 | switch (cmd) { | |
2585 | case TIOCMBIS: | |
2586 | set = val; | |
2587 | break; | |
2588 | case TIOCMBIC: | |
2589 | clear = val; | |
2590 | break; | |
2591 | case TIOCMSET: | |
2592 | set = val; | |
2593 | clear = ~val; | |
2594 | break; | |
2595 | } | |
2596 | set &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
2597 | clear &= TIOCM_DTR|TIOCM_RTS|TIOCM_OUT1|TIOCM_OUT2|TIOCM_LOOP; | |
20b9d177 | 2598 | return tty->ops->tiocmset(tty, set, clear); |
1da177e4 LT |
2599 | } |
2600 | ||
d281da7f AC |
2601 | static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) |
2602 | { | |
2603 | int retval = -EINVAL; | |
2604 | struct serial_icounter_struct icount; | |
2605 | memset(&icount, 0, sizeof(icount)); | |
2606 | if (tty->ops->get_icount) | |
2607 | retval = tty->ops->get_icount(tty, &icount); | |
2608 | if (retval != 0) | |
2609 | return retval; | |
2610 | if (copy_to_user(arg, &icount, sizeof(icount))) | |
2611 | return -EFAULT; | |
2612 | return 0; | |
2613 | } | |
2614 | ||
e8b70e7d AC |
2615 | struct tty_struct *tty_pair_get_tty(struct tty_struct *tty) |
2616 | { | |
2617 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2618 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2619 | tty = tty->link; | |
2620 | return tty; | |
2621 | } | |
2622 | EXPORT_SYMBOL(tty_pair_get_tty); | |
2623 | ||
2624 | struct tty_struct *tty_pair_get_pty(struct tty_struct *tty) | |
2625 | { | |
2626 | if (tty->driver->type == TTY_DRIVER_TYPE_PTY && | |
2627 | tty->driver->subtype == PTY_TYPE_MASTER) | |
2628 | return tty; | |
2629 | return tty->link; | |
2630 | } | |
2631 | EXPORT_SYMBOL(tty_pair_get_pty); | |
2632 | ||
1da177e4 LT |
2633 | /* |
2634 | * Split this up, as gcc can choke on it otherwise.. | |
2635 | */ | |
04f378b1 | 2636 | long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
1da177e4 | 2637 | { |
d996b62a NP |
2638 | struct tty_struct *tty = file_tty(file); |
2639 | struct tty_struct *real_tty; | |
1da177e4 LT |
2640 | void __user *p = (void __user *)arg; |
2641 | int retval; | |
2642 | struct tty_ldisc *ld; | |
04f378b1 | 2643 | struct inode *inode = file->f_dentry->d_inode; |
37bdfb07 | 2644 | |
1da177e4 LT |
2645 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) |
2646 | return -EINVAL; | |
2647 | ||
e8b70e7d | 2648 | real_tty = tty_pair_get_tty(tty); |
1da177e4 LT |
2649 | |
2650 | /* | |
2651 | * Factor out some common prep work | |
2652 | */ | |
2653 | switch (cmd) { | |
2654 | case TIOCSETD: | |
2655 | case TIOCSBRK: | |
2656 | case TIOCCBRK: | |
2657 | case TCSBRK: | |
37bdfb07 | 2658 | case TCSBRKP: |
1da177e4 LT |
2659 | retval = tty_check_change(tty); |
2660 | if (retval) | |
2661 | return retval; | |
2662 | if (cmd != TIOCCBRK) { | |
2663 | tty_wait_until_sent(tty, 0); | |
2664 | if (signal_pending(current)) | |
2665 | return -EINTR; | |
2666 | } | |
2667 | break; | |
2668 | } | |
2669 | ||
9e98966c AC |
2670 | /* |
2671 | * Now do the stuff. | |
2672 | */ | |
1da177e4 | 2673 | switch (cmd) { |
37bdfb07 AC |
2674 | case TIOCSTI: |
2675 | return tiocsti(tty, p); | |
2676 | case TIOCGWINSZ: | |
8f520021 | 2677 | return tiocgwinsz(real_tty, p); |
37bdfb07 | 2678 | case TIOCSWINSZ: |
fc6f6238 | 2679 | return tiocswinsz(real_tty, p); |
37bdfb07 AC |
2680 | case TIOCCONS: |
2681 | return real_tty != tty ? -EINVAL : tioccons(file); | |
2682 | case FIONBIO: | |
2683 | return fionbio(file, p); | |
2684 | case TIOCEXCL: | |
2685 | set_bit(TTY_EXCLUSIVE, &tty->flags); | |
2686 | return 0; | |
2687 | case TIOCNXCL: | |
2688 | clear_bit(TTY_EXCLUSIVE, &tty->flags); | |
2689 | return 0; | |
2690 | case TIOCNOTTY: | |
2691 | if (current->signal->tty != tty) | |
2692 | return -ENOTTY; | |
2693 | no_tty(); | |
2694 | return 0; | |
2695 | case TIOCSCTTY: | |
2696 | return tiocsctty(tty, arg); | |
2697 | case TIOCGPGRP: | |
2698 | return tiocgpgrp(tty, real_tty, p); | |
2699 | case TIOCSPGRP: | |
2700 | return tiocspgrp(tty, real_tty, p); | |
2701 | case TIOCGSID: | |
2702 | return tiocgsid(tty, real_tty, p); | |
2703 | case TIOCGETD: | |
c65c9bc3 | 2704 | return put_user(tty->ldisc->ops->num, (int __user *)p); |
37bdfb07 AC |
2705 | case TIOCSETD: |
2706 | return tiocsetd(tty, p); | |
3c95c985 KS |
2707 | case TIOCVHANGUP: |
2708 | if (!capable(CAP_SYS_ADMIN)) | |
2709 | return -EPERM; | |
2710 | tty_vhangup(tty); | |
2711 | return 0; | |
b7b8de08 WF |
2712 | case TIOCGDEV: |
2713 | { | |
2714 | unsigned int ret = new_encode_dev(tty_devnum(real_tty)); | |
2715 | return put_user(ret, (unsigned int __user *)p); | |
2716 | } | |
37bdfb07 AC |
2717 | /* |
2718 | * Break handling | |
2719 | */ | |
2720 | case TIOCSBRK: /* Turn break on, unconditionally */ | |
f34d7a5b | 2721 | if (tty->ops->break_ctl) |
9e98966c | 2722 | return tty->ops->break_ctl(tty, -1); |
37bdfb07 | 2723 | return 0; |
37bdfb07 | 2724 | case TIOCCBRK: /* Turn break off, unconditionally */ |
f34d7a5b | 2725 | if (tty->ops->break_ctl) |
9e98966c | 2726 | return tty->ops->break_ctl(tty, 0); |
37bdfb07 AC |
2727 | return 0; |
2728 | case TCSBRK: /* SVID version: non-zero arg --> no break */ | |
2729 | /* non-zero arg means wait for all output data | |
2730 | * to be sent (performed above) but don't send break. | |
2731 | * This is used by the tcdrain() termios function. | |
2732 | */ | |
2733 | if (!arg) | |
2734 | return send_break(tty, 250); | |
2735 | return 0; | |
2736 | case TCSBRKP: /* support for POSIX tcsendbreak() */ | |
2737 | return send_break(tty, arg ? arg*100 : 250); | |
2738 | ||
2739 | case TIOCMGET: | |
60b33c13 | 2740 | return tty_tiocmget(tty, p); |
37bdfb07 AC |
2741 | case TIOCMSET: |
2742 | case TIOCMBIC: | |
2743 | case TIOCMBIS: | |
20b9d177 | 2744 | return tty_tiocmset(tty, cmd, p); |
d281da7f AC |
2745 | case TIOCGICOUNT: |
2746 | retval = tty_tiocgicount(tty, p); | |
2747 | /* For the moment allow fall through to the old method */ | |
2748 | if (retval != -EINVAL) | |
2749 | return retval; | |
2750 | break; | |
37bdfb07 AC |
2751 | case TCFLSH: |
2752 | switch (arg) { | |
2753 | case TCIFLUSH: | |
2754 | case TCIOFLUSH: | |
2755 | /* flush tty buffer and allow ldisc to process ioctl */ | |
2756 | tty_buffer_flush(tty); | |
c5c34d48 | 2757 | break; |
37bdfb07 AC |
2758 | } |
2759 | break; | |
1da177e4 | 2760 | } |
f34d7a5b | 2761 | if (tty->ops->ioctl) { |
6caa76b7 | 2762 | retval = (tty->ops->ioctl)(tty, cmd, arg); |
1da177e4 LT |
2763 | if (retval != -ENOIOCTLCMD) |
2764 | return retval; | |
2765 | } | |
2766 | ld = tty_ldisc_ref_wait(tty); | |
2767 | retval = -EINVAL; | |
a352def2 AC |
2768 | if (ld->ops->ioctl) { |
2769 | retval = ld->ops->ioctl(tty, file, cmd, arg); | |
1da177e4 LT |
2770 | if (retval == -ENOIOCTLCMD) |
2771 | retval = -EINVAL; | |
2772 | } | |
2773 | tty_ldisc_deref(ld); | |
2774 | return retval; | |
2775 | } | |
2776 | ||
e10cc1df | 2777 | #ifdef CONFIG_COMPAT |
37bdfb07 | 2778 | static long tty_compat_ioctl(struct file *file, unsigned int cmd, |
e10cc1df PF |
2779 | unsigned long arg) |
2780 | { | |
2781 | struct inode *inode = file->f_dentry->d_inode; | |
d996b62a | 2782 | struct tty_struct *tty = file_tty(file); |
e10cc1df PF |
2783 | struct tty_ldisc *ld; |
2784 | int retval = -ENOIOCTLCMD; | |
2785 | ||
2786 | if (tty_paranoia_check(tty, inode, "tty_ioctl")) | |
2787 | return -EINVAL; | |
2788 | ||
f34d7a5b | 2789 | if (tty->ops->compat_ioctl) { |
6caa76b7 | 2790 | retval = (tty->ops->compat_ioctl)(tty, cmd, arg); |
e10cc1df PF |
2791 | if (retval != -ENOIOCTLCMD) |
2792 | return retval; | |
2793 | } | |
2794 | ||
2795 | ld = tty_ldisc_ref_wait(tty); | |
a352def2 AC |
2796 | if (ld->ops->compat_ioctl) |
2797 | retval = ld->ops->compat_ioctl(tty, file, cmd, arg); | |
8193c429 TM |
2798 | else |
2799 | retval = n_tty_compat_ioctl_helper(tty, file, cmd, arg); | |
e10cc1df PF |
2800 | tty_ldisc_deref(ld); |
2801 | ||
2802 | return retval; | |
2803 | } | |
2804 | #endif | |
1da177e4 LT |
2805 | |
2806 | /* | |
2807 | * This implements the "Secure Attention Key" --- the idea is to | |
2808 | * prevent trojan horses by killing all processes associated with this | |
2809 | * tty when the user hits the "Secure Attention Key". Required for | |
2810 | * super-paranoid applications --- see the Orange Book for more details. | |
37bdfb07 | 2811 | * |
1da177e4 LT |
2812 | * This code could be nicer; ideally it should send a HUP, wait a few |
2813 | * seconds, then send a INT, and then a KILL signal. But you then | |
2814 | * have to coordinate with the init process, since all processes associated | |
2815 | * with the current tty must be dead before the new getty is allowed | |
2816 | * to spawn. | |
2817 | * | |
2818 | * Now, if it would be correct ;-/ The current code has a nasty hole - | |
2819 | * it doesn't catch files in flight. We may send the descriptor to ourselves | |
2820 | * via AF_UNIX socket, close it and later fetch from socket. FIXME. | |
2821 | * | |
2822 | * Nasty bug: do_SAK is being called in interrupt context. This can | |
2823 | * deadlock. We punt it up to process context. AKPM - 16Mar2001 | |
2824 | */ | |
8b6312f4 | 2825 | void __do_SAK(struct tty_struct *tty) |
1da177e4 LT |
2826 | { |
2827 | #ifdef TTY_SOFT_SAK | |
2828 | tty_hangup(tty); | |
2829 | #else | |
652486fb | 2830 | struct task_struct *g, *p; |
ab521dc0 | 2831 | struct pid *session; |
1da177e4 LT |
2832 | int i; |
2833 | struct file *filp; | |
badf1662 | 2834 | struct fdtable *fdt; |
37bdfb07 | 2835 | |
1da177e4 LT |
2836 | if (!tty) |
2837 | return; | |
24ec839c | 2838 | session = tty->session; |
37bdfb07 | 2839 | |
b3f13deb | 2840 | tty_ldisc_flush(tty); |
1da177e4 | 2841 | |
f34d7a5b | 2842 | tty_driver_flush_buffer(tty); |
37bdfb07 | 2843 | |
1da177e4 | 2844 | read_lock(&tasklist_lock); |
652486fb | 2845 | /* Kill the entire session */ |
ab521dc0 | 2846 | do_each_pid_task(session, PIDTYPE_SID, p) { |
652486fb | 2847 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2848 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2849 | task_pid_nr(p), p->comm); |
652486fb | 2850 | send_sig(SIGKILL, p, 1); |
ab521dc0 | 2851 | } while_each_pid_task(session, PIDTYPE_SID, p); |
652486fb EB |
2852 | /* Now kill any processes that happen to have the |
2853 | * tty open. | |
2854 | */ | |
2855 | do_each_thread(g, p) { | |
2856 | if (p->signal->tty == tty) { | |
1da177e4 | 2857 | printk(KERN_NOTICE "SAK: killed process %d" |
1b0f7ffd | 2858 | " (%s): task_session(p)==tty->session\n", |
ba25f9dc | 2859 | task_pid_nr(p), p->comm); |
1da177e4 LT |
2860 | send_sig(SIGKILL, p, 1); |
2861 | continue; | |
2862 | } | |
2863 | task_lock(p); | |
2864 | if (p->files) { | |
ca99c1da DS |
2865 | /* |
2866 | * We don't take a ref to the file, so we must | |
2867 | * hold ->file_lock instead. | |
2868 | */ | |
2869 | spin_lock(&p->files->file_lock); | |
badf1662 | 2870 | fdt = files_fdtable(p->files); |
37bdfb07 | 2871 | for (i = 0; i < fdt->max_fds; i++) { |
1da177e4 LT |
2872 | filp = fcheck_files(p->files, i); |
2873 | if (!filp) | |
2874 | continue; | |
2875 | if (filp->f_op->read == tty_read && | |
d996b62a | 2876 | file_tty(filp) == tty) { |
1da177e4 LT |
2877 | printk(KERN_NOTICE "SAK: killed process %d" |
2878 | " (%s): fd#%d opened to the tty\n", | |
ba25f9dc | 2879 | task_pid_nr(p), p->comm, i); |
20ac9437 | 2880 | force_sig(SIGKILL, p); |
1da177e4 LT |
2881 | break; |
2882 | } | |
2883 | } | |
ca99c1da | 2884 | spin_unlock(&p->files->file_lock); |
1da177e4 LT |
2885 | } |
2886 | task_unlock(p); | |
652486fb | 2887 | } while_each_thread(g, p); |
1da177e4 LT |
2888 | read_unlock(&tasklist_lock); |
2889 | #endif | |
2890 | } | |
2891 | ||
8b6312f4 EB |
2892 | static void do_SAK_work(struct work_struct *work) |
2893 | { | |
2894 | struct tty_struct *tty = | |
2895 | container_of(work, struct tty_struct, SAK_work); | |
2896 | __do_SAK(tty); | |
2897 | } | |
2898 | ||
1da177e4 LT |
2899 | /* |
2900 | * The tq handling here is a little racy - tty->SAK_work may already be queued. | |
2901 | * Fortunately we don't need to worry, because if ->SAK_work is already queued, | |
2902 | * the values which we write to it will be identical to the values which it | |
2903 | * already has. --akpm | |
2904 | */ | |
2905 | void do_SAK(struct tty_struct *tty) | |
2906 | { | |
2907 | if (!tty) | |
2908 | return; | |
1da177e4 LT |
2909 | schedule_work(&tty->SAK_work); |
2910 | } | |
2911 | ||
2912 | EXPORT_SYMBOL(do_SAK); | |
2913 | ||
30004ac9 DES |
2914 | static int dev_match_devt(struct device *dev, void *data) |
2915 | { | |
2916 | dev_t *devt = data; | |
2917 | return dev->devt == *devt; | |
2918 | } | |
2919 | ||
2920 | /* Must put_device() after it's unused! */ | |
2921 | static struct device *tty_get_device(struct tty_struct *tty) | |
2922 | { | |
2923 | dev_t devt = tty_devnum(tty); | |
2924 | return class_find_device(tty_class, NULL, &devt, dev_match_devt); | |
2925 | } | |
2926 | ||
2927 | ||
af9b897e AC |
2928 | /** |
2929 | * initialize_tty_struct | |
2930 | * @tty: tty to initialize | |
2931 | * | |
2932 | * This subroutine initializes a tty structure that has been newly | |
2933 | * allocated. | |
2934 | * | |
2935 | * Locking: none - tty in question must not be exposed at this point | |
1da177e4 | 2936 | */ |
af9b897e | 2937 | |
bf970ee4 AC |
2938 | void initialize_tty_struct(struct tty_struct *tty, |
2939 | struct tty_driver *driver, int idx) | |
1da177e4 LT |
2940 | { |
2941 | memset(tty, 0, sizeof(struct tty_struct)); | |
9c9f4ded | 2942 | kref_init(&tty->kref); |
1da177e4 | 2943 | tty->magic = TTY_MAGIC; |
01e1abb2 | 2944 | tty_ldisc_init(tty); |
ab521dc0 EB |
2945 | tty->session = NULL; |
2946 | tty->pgrp = NULL; | |
1da177e4 | 2947 | tty->overrun_time = jiffies; |
33f0f88f | 2948 | tty_buffer_init(tty); |
d29f3ef3 | 2949 | mutex_init(&tty->legacy_mutex); |
5785c95b | 2950 | mutex_init(&tty->termios_mutex); |
c65c9bc3 | 2951 | mutex_init(&tty->ldisc_mutex); |
1da177e4 LT |
2952 | init_waitqueue_head(&tty->write_wait); |
2953 | init_waitqueue_head(&tty->read_wait); | |
65f27f38 | 2954 | INIT_WORK(&tty->hangup_work, do_tty_hangup); |
70522e12 IM |
2955 | mutex_init(&tty->atomic_read_lock); |
2956 | mutex_init(&tty->atomic_write_lock); | |
a88a69c9 JP |
2957 | mutex_init(&tty->output_lock); |
2958 | mutex_init(&tty->echo_lock); | |
1da177e4 | 2959 | spin_lock_init(&tty->read_lock); |
04f378b1 | 2960 | spin_lock_init(&tty->ctrl_lock); |
1da177e4 | 2961 | INIT_LIST_HEAD(&tty->tty_files); |
7f1f86a0 | 2962 | INIT_WORK(&tty->SAK_work, do_SAK_work); |
bf970ee4 AC |
2963 | |
2964 | tty->driver = driver; | |
2965 | tty->ops = driver->ops; | |
2966 | tty->index = idx; | |
2967 | tty_line_name(driver, idx, tty->name); | |
30004ac9 | 2968 | tty->dev = tty_get_device(tty); |
1da177e4 LT |
2969 | } |
2970 | ||
6716671d JS |
2971 | /** |
2972 | * deinitialize_tty_struct | |
2973 | * @tty: tty to deinitialize | |
2974 | * | |
2975 | * This subroutine deinitializes a tty structure that has been newly | |
2976 | * allocated but tty_release cannot be called on that yet. | |
2977 | * | |
2978 | * Locking: none - tty in question must not be exposed at this point | |
2979 | */ | |
2980 | void deinitialize_tty_struct(struct tty_struct *tty) | |
2981 | { | |
2982 | tty_ldisc_deinit(tty); | |
2983 | } | |
2984 | ||
f34d7a5b AC |
2985 | /** |
2986 | * tty_put_char - write one character to a tty | |
2987 | * @tty: tty | |
2988 | * @ch: character | |
2989 | * | |
2990 | * Write one byte to the tty using the provided put_char method | |
2991 | * if present. Returns the number of characters successfully output. | |
2992 | * | |
2993 | * Note: the specific put_char operation in the driver layer may go | |
2994 | * away soon. Don't call it directly, use this method | |
1da177e4 | 2995 | */ |
af9b897e | 2996 | |
f34d7a5b | 2997 | int tty_put_char(struct tty_struct *tty, unsigned char ch) |
1da177e4 | 2998 | { |
f34d7a5b AC |
2999 | if (tty->ops->put_char) |
3000 | return tty->ops->put_char(tty, ch); | |
3001 | return tty->ops->write(tty, &ch, 1); | |
1da177e4 | 3002 | } |
f34d7a5b AC |
3003 | EXPORT_SYMBOL_GPL(tty_put_char); |
3004 | ||
d81ed103 | 3005 | struct class *tty_class; |
1da177e4 LT |
3006 | |
3007 | /** | |
af9b897e AC |
3008 | * tty_register_device - register a tty device |
3009 | * @driver: the tty driver that describes the tty device | |
3010 | * @index: the index in the tty driver for this tty device | |
3011 | * @device: a struct device that is associated with this tty device. | |
3012 | * This field is optional, if there is no known struct device | |
3013 | * for this tty device it can be set to NULL safely. | |
1da177e4 | 3014 | * |
01107d34 GKH |
3015 | * Returns a pointer to the struct device for this tty device |
3016 | * (or ERR_PTR(-EFOO) on error). | |
1cdcb6b4 | 3017 | * |
af9b897e AC |
3018 | * This call is required to be made to register an individual tty device |
3019 | * if the tty driver's flags have the TTY_DRIVER_DYNAMIC_DEV bit set. If | |
3020 | * that bit is not set, this function should not be called by a tty | |
3021 | * driver. | |
3022 | * | |
3023 | * Locking: ?? | |
1da177e4 | 3024 | */ |
af9b897e | 3025 | |
01107d34 GKH |
3026 | struct device *tty_register_device(struct tty_driver *driver, unsigned index, |
3027 | struct device *device) | |
1da177e4 LT |
3028 | { |
3029 | char name[64]; | |
3030 | dev_t dev = MKDEV(driver->major, driver->minor_start) + index; | |
3031 | ||
3032 | if (index >= driver->num) { | |
3033 | printk(KERN_ERR "Attempt to register invalid tty line number " | |
3034 | " (%d).\n", index); | |
1cdcb6b4 | 3035 | return ERR_PTR(-EINVAL); |
1da177e4 LT |
3036 | } |
3037 | ||
1da177e4 LT |
3038 | if (driver->type == TTY_DRIVER_TYPE_PTY) |
3039 | pty_line_name(driver, index, name); | |
3040 | else | |
3041 | tty_line_name(driver, index, name); | |
1cdcb6b4 | 3042 | |
03457cd4 | 3043 | return device_create(tty_class, device, dev, NULL, name); |
1da177e4 | 3044 | } |
7d7b93c1 | 3045 | EXPORT_SYMBOL(tty_register_device); |
1da177e4 LT |
3046 | |
3047 | /** | |
af9b897e AC |
3048 | * tty_unregister_device - unregister a tty device |
3049 | * @driver: the tty driver that describes the tty device | |
3050 | * @index: the index in the tty driver for this tty device | |
1da177e4 | 3051 | * |
af9b897e AC |
3052 | * If a tty device is registered with a call to tty_register_device() then |
3053 | * this function must be called when the tty device is gone. | |
3054 | * | |
3055 | * Locking: ?? | |
1da177e4 | 3056 | */ |
af9b897e | 3057 | |
1da177e4 LT |
3058 | void tty_unregister_device(struct tty_driver *driver, unsigned index) |
3059 | { | |
37bdfb07 AC |
3060 | device_destroy(tty_class, |
3061 | MKDEV(driver->major, driver->minor_start) + index); | |
1da177e4 | 3062 | } |
1da177e4 LT |
3063 | EXPORT_SYMBOL(tty_unregister_device); |
3064 | ||
1a54a76d | 3065 | struct tty_driver *__alloc_tty_driver(int lines, struct module *owner) |
1da177e4 LT |
3066 | { |
3067 | struct tty_driver *driver; | |
3068 | ||
506eb99a | 3069 | driver = kzalloc(sizeof(struct tty_driver), GFP_KERNEL); |
1da177e4 | 3070 | if (driver) { |
7d7b93c1 | 3071 | kref_init(&driver->kref); |
1da177e4 LT |
3072 | driver->magic = TTY_DRIVER_MAGIC; |
3073 | driver->num = lines; | |
1a54a76d | 3074 | driver->owner = owner; |
1da177e4 LT |
3075 | /* later we'll move allocation of tables here */ |
3076 | } | |
3077 | return driver; | |
3078 | } | |
1a54a76d | 3079 | EXPORT_SYMBOL(__alloc_tty_driver); |
1da177e4 | 3080 | |
7d7b93c1 | 3081 | static void destruct_tty_driver(struct kref *kref) |
1da177e4 | 3082 | { |
7d7b93c1 AC |
3083 | struct tty_driver *driver = container_of(kref, struct tty_driver, kref); |
3084 | int i; | |
3085 | struct ktermios *tp; | |
3086 | void *p; | |
3087 | ||
3088 | if (driver->flags & TTY_DRIVER_INSTALLED) { | |
3089 | /* | |
3090 | * Free the termios and termios_locked structures because | |
3091 | * we don't want to get memory leaks when modular tty | |
3092 | * drivers are removed from the kernel. | |
3093 | */ | |
3094 | for (i = 0; i < driver->num; i++) { | |
3095 | tp = driver->termios[i]; | |
3096 | if (tp) { | |
3097 | driver->termios[i] = NULL; | |
3098 | kfree(tp); | |
3099 | } | |
7d7b93c1 AC |
3100 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) |
3101 | tty_unregister_device(driver, i); | |
3102 | } | |
3103 | p = driver->ttys; | |
3104 | proc_tty_unregister_driver(driver); | |
3105 | driver->ttys = NULL; | |
fe6e29fd | 3106 | driver->termios = NULL; |
7d7b93c1 AC |
3107 | kfree(p); |
3108 | cdev_del(&driver->cdev); | |
3109 | } | |
1da177e4 LT |
3110 | kfree(driver); |
3111 | } | |
3112 | ||
7d7b93c1 AC |
3113 | void tty_driver_kref_put(struct tty_driver *driver) |
3114 | { | |
3115 | kref_put(&driver->kref, destruct_tty_driver); | |
3116 | } | |
3117 | EXPORT_SYMBOL(tty_driver_kref_put); | |
3118 | ||
b68e31d0 JD |
3119 | void tty_set_operations(struct tty_driver *driver, |
3120 | const struct tty_operations *op) | |
1da177e4 | 3121 | { |
f34d7a5b AC |
3122 | driver->ops = op; |
3123 | }; | |
7d7b93c1 | 3124 | EXPORT_SYMBOL(tty_set_operations); |
1da177e4 | 3125 | |
7d7b93c1 AC |
3126 | void put_tty_driver(struct tty_driver *d) |
3127 | { | |
3128 | tty_driver_kref_put(d); | |
3129 | } | |
1da177e4 | 3130 | EXPORT_SYMBOL(put_tty_driver); |
1da177e4 LT |
3131 | |
3132 | /* | |
3133 | * Called by a tty driver to register itself. | |
3134 | */ | |
3135 | int tty_register_driver(struct tty_driver *driver) | |
3136 | { | |
3137 | int error; | |
37bdfb07 | 3138 | int i; |
1da177e4 LT |
3139 | dev_t dev; |
3140 | void **p = NULL; | |
b670bde0 | 3141 | struct device *d; |
1da177e4 | 3142 | |
543691a6 | 3143 | if (!(driver->flags & TTY_DRIVER_DEVPTS_MEM) && driver->num) { |
fe6e29fd | 3144 | p = kzalloc(driver->num * 2 * sizeof(void *), GFP_KERNEL); |
1da177e4 LT |
3145 | if (!p) |
3146 | return -ENOMEM; | |
1da177e4 LT |
3147 | } |
3148 | ||
3149 | if (!driver->major) { | |
37bdfb07 AC |
3150 | error = alloc_chrdev_region(&dev, driver->minor_start, |
3151 | driver->num, driver->name); | |
1da177e4 LT |
3152 | if (!error) { |
3153 | driver->major = MAJOR(dev); | |
3154 | driver->minor_start = MINOR(dev); | |
3155 | } | |
3156 | } else { | |
3157 | dev = MKDEV(driver->major, driver->minor_start); | |
e5717c48 | 3158 | error = register_chrdev_region(dev, driver->num, driver->name); |
1da177e4 LT |
3159 | } |
3160 | if (error < 0) { | |
3161 | kfree(p); | |
3162 | return error; | |
3163 | } | |
3164 | ||
3165 | if (p) { | |
3166 | driver->ttys = (struct tty_struct **)p; | |
edc6afc5 | 3167 | driver->termios = (struct ktermios **)(p + driver->num); |
1da177e4 LT |
3168 | } else { |
3169 | driver->ttys = NULL; | |
3170 | driver->termios = NULL; | |
1da177e4 LT |
3171 | } |
3172 | ||
3173 | cdev_init(&driver->cdev, &tty_fops); | |
3174 | driver->cdev.owner = driver->owner; | |
3175 | error = cdev_add(&driver->cdev, dev, driver->num); | |
3176 | if (error) { | |
1da177e4 LT |
3177 | unregister_chrdev_region(dev, driver->num); |
3178 | driver->ttys = NULL; | |
fe6e29fd | 3179 | driver->termios = NULL; |
1da177e4 LT |
3180 | kfree(p); |
3181 | return error; | |
3182 | } | |
3183 | ||
ca509f69 | 3184 | mutex_lock(&tty_mutex); |
1da177e4 | 3185 | list_add(&driver->tty_drivers, &tty_drivers); |
ca509f69 | 3186 | mutex_unlock(&tty_mutex); |
37bdfb07 AC |
3187 | |
3188 | if (!(driver->flags & TTY_DRIVER_DYNAMIC_DEV)) { | |
b670bde0 VK |
3189 | for (i = 0; i < driver->num; i++) { |
3190 | d = tty_register_device(driver, i, NULL); | |
3191 | if (IS_ERR(d)) { | |
3192 | error = PTR_ERR(d); | |
3193 | goto err; | |
3194 | } | |
3195 | } | |
1da177e4 LT |
3196 | } |
3197 | proc_tty_register_driver(driver); | |
7d7b93c1 | 3198 | driver->flags |= TTY_DRIVER_INSTALLED; |
1da177e4 | 3199 | return 0; |
b670bde0 VK |
3200 | |
3201 | err: | |
3202 | for (i--; i >= 0; i--) | |
3203 | tty_unregister_device(driver, i); | |
3204 | ||
3205 | mutex_lock(&tty_mutex); | |
3206 | list_del(&driver->tty_drivers); | |
3207 | mutex_unlock(&tty_mutex); | |
3208 | ||
3209 | unregister_chrdev_region(dev, driver->num); | |
3210 | driver->ttys = NULL; | |
3211 | driver->termios = NULL; | |
3212 | kfree(p); | |
3213 | return error; | |
1da177e4 LT |
3214 | } |
3215 | ||
3216 | EXPORT_SYMBOL(tty_register_driver); | |
3217 | ||
3218 | /* | |
3219 | * Called by a tty driver to unregister itself. | |
3220 | */ | |
3221 | int tty_unregister_driver(struct tty_driver *driver) | |
3222 | { | |
7d7b93c1 AC |
3223 | #if 0 |
3224 | /* FIXME */ | |
1da177e4 LT |
3225 | if (driver->refcount) |
3226 | return -EBUSY; | |
7d7b93c1 | 3227 | #endif |
1da177e4 LT |
3228 | unregister_chrdev_region(MKDEV(driver->major, driver->minor_start), |
3229 | driver->num); | |
ca509f69 | 3230 | mutex_lock(&tty_mutex); |
1da177e4 | 3231 | list_del(&driver->tty_drivers); |
ca509f69 | 3232 | mutex_unlock(&tty_mutex); |
1da177e4 LT |
3233 | return 0; |
3234 | } | |
7d7b93c1 | 3235 | |
1da177e4 LT |
3236 | EXPORT_SYMBOL(tty_unregister_driver); |
3237 | ||
24ec839c PZ |
3238 | dev_t tty_devnum(struct tty_struct *tty) |
3239 | { | |
3240 | return MKDEV(tty->driver->major, tty->driver->minor_start) + tty->index; | |
3241 | } | |
3242 | EXPORT_SYMBOL(tty_devnum); | |
3243 | ||
3244 | void proc_clear_tty(struct task_struct *p) | |
3245 | { | |
7c3b1dcf | 3246 | unsigned long flags; |
9c9f4ded | 3247 | struct tty_struct *tty; |
7c3b1dcf | 3248 | spin_lock_irqsave(&p->sighand->siglock, flags); |
9c9f4ded | 3249 | tty = p->signal->tty; |
24ec839c | 3250 | p->signal->tty = NULL; |
7c3b1dcf | 3251 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
9c9f4ded | 3252 | tty_kref_put(tty); |
24ec839c | 3253 | } |
24ec839c | 3254 | |
47f86834 AC |
3255 | /* Called under the sighand lock */ |
3256 | ||
2a65f1d9 | 3257 | static void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3258 | { |
3259 | if (tty) { | |
47f86834 AC |
3260 | unsigned long flags; |
3261 | /* We should not have a session or pgrp to put here but.... */ | |
3262 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
d9c1e9a8 EB |
3263 | put_pid(tty->session); |
3264 | put_pid(tty->pgrp); | |
ab521dc0 | 3265 | tty->pgrp = get_pid(task_pgrp(tsk)); |
47f86834 AC |
3266 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
3267 | tty->session = get_pid(task_session(tsk)); | |
9c9f4ded AC |
3268 | if (tsk->signal->tty) { |
3269 | printk(KERN_DEBUG "tty not NULL!!\n"); | |
3270 | tty_kref_put(tsk->signal->tty); | |
3271 | } | |
24ec839c | 3272 | } |
2a65f1d9 | 3273 | put_pid(tsk->signal->tty_old_pgrp); |
9c9f4ded | 3274 | tsk->signal->tty = tty_kref_get(tty); |
ab521dc0 | 3275 | tsk->signal->tty_old_pgrp = NULL; |
24ec839c PZ |
3276 | } |
3277 | ||
98a27ba4 | 3278 | static void proc_set_tty(struct task_struct *tsk, struct tty_struct *tty) |
24ec839c PZ |
3279 | { |
3280 | spin_lock_irq(&tsk->sighand->siglock); | |
2a65f1d9 | 3281 | __proc_set_tty(tsk, tty); |
24ec839c PZ |
3282 | spin_unlock_irq(&tsk->sighand->siglock); |
3283 | } | |
3284 | ||
3285 | struct tty_struct *get_current_tty(void) | |
3286 | { | |
3287 | struct tty_struct *tty; | |
934e6ebf AC |
3288 | unsigned long flags; |
3289 | ||
3290 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
452a00d2 | 3291 | tty = tty_kref_get(current->signal->tty); |
934e6ebf | 3292 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
24ec839c PZ |
3293 | return tty; |
3294 | } | |
a311f743 | 3295 | EXPORT_SYMBOL_GPL(get_current_tty); |
1da177e4 | 3296 | |
d81ed103 AC |
3297 | void tty_default_fops(struct file_operations *fops) |
3298 | { | |
3299 | *fops = tty_fops; | |
3300 | } | |
3301 | ||
1da177e4 LT |
3302 | /* |
3303 | * Initialize the console device. This is called *early*, so | |
3304 | * we can't necessarily depend on lots of kernel help here. | |
3305 | * Just do some early initializations, and do the complex setup | |
3306 | * later. | |
3307 | */ | |
3308 | void __init console_init(void) | |
3309 | { | |
3310 | initcall_t *call; | |
3311 | ||
3312 | /* Setup the default TTY line discipline. */ | |
01e1abb2 | 3313 | tty_ldisc_begin(); |
1da177e4 LT |
3314 | |
3315 | /* | |
37bdfb07 | 3316 | * set up the console device so that later boot sequences can |
1da177e4 LT |
3317 | * inform about problems etc.. |
3318 | */ | |
1da177e4 LT |
3319 | call = __con_initcall_start; |
3320 | while (call < __con_initcall_end) { | |
3321 | (*call)(); | |
3322 | call++; | |
3323 | } | |
3324 | } | |
3325 | ||
2c9ede55 | 3326 | static char *tty_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
3327 | { |
3328 | if (!mode) | |
3329 | return NULL; | |
3330 | if (dev->devt == MKDEV(TTYAUX_MAJOR, 0) || | |
3331 | dev->devt == MKDEV(TTYAUX_MAJOR, 2)) | |
3332 | *mode = 0666; | |
3333 | return NULL; | |
3334 | } | |
3335 | ||
1da177e4 LT |
3336 | static int __init tty_class_init(void) |
3337 | { | |
7fe845d1 | 3338 | tty_class = class_create(THIS_MODULE, "tty"); |
1da177e4 LT |
3339 | if (IS_ERR(tty_class)) |
3340 | return PTR_ERR(tty_class); | |
e454cea2 | 3341 | tty_class->devnode = tty_devnode; |
1da177e4 LT |
3342 | return 0; |
3343 | } | |
3344 | ||
3345 | postcore_initcall(tty_class_init); | |
3346 | ||
3347 | /* 3/2004 jmc: why do these devices exist? */ | |
1da177e4 | 3348 | static struct cdev tty_cdev, console_cdev; |
1da177e4 | 3349 | |
fbc92a34 KS |
3350 | static ssize_t show_cons_active(struct device *dev, |
3351 | struct device_attribute *attr, char *buf) | |
3352 | { | |
3353 | struct console *cs[16]; | |
3354 | int i = 0; | |
3355 | struct console *c; | |
3356 | ssize_t count = 0; | |
3357 | ||
ac751efa | 3358 | console_lock(); |
a2a6a822 | 3359 | for_each_console(c) { |
fbc92a34 KS |
3360 | if (!c->device) |
3361 | continue; | |
3362 | if (!c->write) | |
3363 | continue; | |
3364 | if ((c->flags & CON_ENABLED) == 0) | |
3365 | continue; | |
3366 | cs[i++] = c; | |
3367 | if (i >= ARRAY_SIZE(cs)) | |
3368 | break; | |
3369 | } | |
3370 | while (i--) | |
3371 | count += sprintf(buf + count, "%s%d%c", | |
3372 | cs[i]->name, cs[i]->index, i ? ' ':'\n'); | |
ac751efa | 3373 | console_unlock(); |
fbc92a34 KS |
3374 | |
3375 | return count; | |
3376 | } | |
3377 | static DEVICE_ATTR(active, S_IRUGO, show_cons_active, NULL); | |
3378 | ||
3379 | static struct device *consdev; | |
3380 | ||
3381 | void console_sysfs_notify(void) | |
3382 | { | |
3383 | if (consdev) | |
3384 | sysfs_notify(&consdev->kobj, NULL, "active"); | |
3385 | } | |
3386 | ||
1da177e4 LT |
3387 | /* |
3388 | * Ok, now we can initialize the rest of the tty devices and can count | |
3389 | * on memory allocations, interrupts etc.. | |
3390 | */ | |
31d1d48e | 3391 | int __init tty_init(void) |
1da177e4 LT |
3392 | { |
3393 | cdev_init(&tty_cdev, &tty_fops); | |
3394 | if (cdev_add(&tty_cdev, MKDEV(TTYAUX_MAJOR, 0), 1) || | |
3395 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 0), 1, "/dev/tty") < 0) | |
3396 | panic("Couldn't register /dev/tty driver\n"); | |
fbc92a34 | 3397 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 0), NULL, "tty"); |
1da177e4 LT |
3398 | |
3399 | cdev_init(&console_cdev, &console_fops); | |
3400 | if (cdev_add(&console_cdev, MKDEV(TTYAUX_MAJOR, 1), 1) || | |
3401 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 1), 1, "/dev/console") < 0) | |
3402 | panic("Couldn't register /dev/console driver\n"); | |
fbc92a34 | 3403 | consdev = device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 1), NULL, |
47aa5793 | 3404 | "console"); |
fbc92a34 KS |
3405 | if (IS_ERR(consdev)) |
3406 | consdev = NULL; | |
3407 | else | |
a2a6a822 | 3408 | WARN_ON(device_create_file(consdev, &dev_attr_active) < 0); |
1da177e4 | 3409 | |
1da177e4 | 3410 | #ifdef CONFIG_VT |
d81ed103 | 3411 | vty_init(&console_fops); |
1da177e4 LT |
3412 | #endif |
3413 | return 0; | |
3414 | } | |
31d1d48e | 3415 |